1,387 research outputs found
Benthophilus persicus Kovacic, Esmaeili, Zarei, Abbasi & Schliewen 2021
No full text16. Benthophilus persicus Kovačić, Esmaeili, Zarei, Abbasi & Schliewen, 2021 (Fig. 13), Persian Tadpole Goby Benthophilus persicus Kovačić, Esmaeili, Zarei, Abbasi & Schliewen, 2021: 47, figs. 2–7; type locality: off Anzali, South Caspian Sea, Gilan Province, Iran, 37°29’N, 49°29’E; holotype: ZSM 47595, male, 55.1 mm TL, paratypes: PMR VP4679, VP4680, VP4681, VP4682, VP4683, ZM-CBSU 5003-128, 5001-1, 5003-60, 5022- 23, 5024-1, 5003-77; ZSM 47596, 47597, 47598, 47599, additional material: ZM-CBSU S003-17 (21), ZMCBSU S003-112–113 (2), ZM-CBSU S003-115 (1), ZM-CBSU S003-134 – 135 (2). Etymology: Named for Persia, the historic region of southwestern Asia that is associated with the area that is now Iran. Distribution and habitat: This species is abundant on sandy bottoms in coastal areas of western South Caspian Sea (Fig. 8C). Eurybathic, depth ranges usually from 6– 70 m. However, no specimens have yet been collected in the eastern part of the South Caspian Sea (Kovačić et al. 2021). Material examined: PMR, ZM-CBSU, and ZSM (type material), plus additional non-type material (Kovačić et al. 2021); ZM-CBSU S003, 116, off Anzali; ZM-CBSU S016, 25, off Astara; ZM-CBSU S022, 30, off Chaboksar; ZM-CBSU S024, 1, & ZM-CBSU S025, 81, off Chamkhaleh; ZM-CBSU S026, 4, Shafaroud mouth; ZMCBSU S029, 3, off Talesh, Gilan Province, Iran. IUCN: NE.Published as part of Zarei, Fatah, Esmaeili, Hamid Reza, Abbasi, Keyvan, Kovačić, Marcelo, Schliewen, Ulrich K. & Stepien, Carol A., 2022, Gobies (Teleostei: Gobiidae) of the oldest and deepest Caspian Sea sub-basin: an evidence-based annotated checklist and a key for species identification, pp. 151-193 in Zootaxa 5190 (2) on pages 168-169, DOI: 10.11646/zootaxa.5190.2.1, http://zenodo.org/record/712006
High activity and high functional connectivity are mutually exclusive in resting state zebrafish and human brains
No full textZarei, M., Xie, D., Jiang, F. et al. High activity and high functional connectivity are mutually exclusive in resting state zebrafish and human brains. BMC Biol 20, 84 (2022). https://doi.org/10.1186/s12915-022-01286-3
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Oxyurichthys omanensis sp. nov., a new Eyebrow Goby (Teleostei: Gobiidae) from Oman
No full textZarei, Fatah, Al Jufaili, Saud M., Esmaeili, Hamid Reza (2022): Oxyurichthys omanensis sp. nov., a new Eyebrow Goby (Teleostei: Gobiidae) from Oman. Zootaxa 5182 (4): 361-376, DOI: 10.11646/zootaxa.5182.4.
Induced Circular Polarization on Photons Due to Interaction with Axion-Like Particles in Rotating Magnetic Field of Neutron Stars
No full textWe investigate how the photon polarization is affected by the interaction
with axion-like particles (ALPs) in the rotating magnetic field of a neutron
star (NS). Using quantum Boltzmann equations the study demonstrates that the
periodic magnetic field of millisecond NSs enhances the interaction of photons
with ALPs and creates a circular polarization on them. A binary system
including an NS and a companion star could serve as a probe. When the NS is in
front of the companion star with respect to the earth observer, there is a
circular polarization on the previously linearly polarized photons as a result
of the interaction with ALPs there. After a half-binary period, the companion
star passes in front of the NS, and the circular polarization of photons
disappears and changes to linear. The excluded parameter space for a
millisecond NS with 300~Hz rotating frequency, highlights the coupling constant
of for the ALP masses in
the range of .Comment: 33 pages, 5 figure
Probing virtual ALPs by precision phase measurements: time-varying magnetic field background
No full textWe propose an experimental scheme for detecting the effects of off-shell axion-like particles (ALPs) through optical cavities. In this proposed experiment, linearly polarized photons are pumped into an optical cavity where an external time-dependent magnetic field is present. The magnetic field mediates an interaction between the cavity photons and ALPs giving rise to a modification in the phase of the cavity photons. The time-dependent nature of the external magnetic field prompts a novel amplification effect which significantly enhances this phase modification. A detection scheme is then proposed to identify such axion-induced phase shifts. We find that the phase modification is considerably sensitive to the photon-ALPs coupling constants ga.y.y for the range of ALPs mass 3.1 mu eV S ma S 44.4 mu eV
Open Quantum System Approach to the Gravitational Decoherence of Spin-1/2 Particles
No full textThis paper investigates the decoherence effect resulting from the interaction
of squeezed gravitational waves with a system of massive particles in spatial
superposition. This paper investigates the decoherence effect resulting from
the interaction of squeezed gravitational waves with a system of massive
particles in spatial superposition. We first employ the open quantum system
approach to obtain the established decoherence in a spatial superposition of
massive objects induced by squeezed gravitational waves. Subsequently, we focus
on the spin-1/2 particle system, and our analysis reveals that the decoherence
rate depends on both the squeezing strength and the squeezing angle of the
gravitational waves. Our results demonstrate that squeezed gravitational waves
with squeezing strengths of and a squeezing angle of
can induce a 1 % decoherence within 1 s free falling of a
cloud of spin-1/2 particles. This investigation sheds light on the relationship
between squeezed gravitational waves and the coherence of spatial superposition
states in systems of massive particles and their spin. The dependence of
decoherence on squeezing strength and, in the case of spin- particles, on
the squeezing angle paves the way for further exploration and understanding of
the quantum-gravity connection. We suggest that such an experimental setup
could also be employed to eventually investigate the level of squeezing effect
(and hence quantum-related properties) of gravitational waves produced in the
early universe from inflation.Comment: 44 pages, 8 figure
A hybrid approach to achieve organizational agility: An empirical study of a food company
No full textPurpose: In today’s intense global competition, agility is advocated as a fundamental characteristic for business survival and competitiveness. The purpose of this paper is to propose a practical methodology to achieve and enhance organizational agility based on strategic objectives. Design/methodology/approach: In the first step, a set of key performance indicators (KPIs) of the organization being studied are recognized and classified under the perspectives of balanced scorecard (BSC). Critical success factors are then identified by ranking the KPIs according to their importance in achieving organizational strategic objectives using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). In the second step, three houses of quality (HOQs) are constructed sequentially to identify and rank the main agile attributes, agile enablers, and improvement paths. In addition, in order to translate linguistics judgments of practitioners into numerical values in building HOQs, fuzzy logic is employed. Findings: The capability of the proposed methodology is demonstrated by applying it to a case of a multi-national food company in Iran. Through the application, the company could find the most suitable improvement paths to improve its organizational agility. Research limitations/implications: A limited number of KPIs were chosen due to computational and visual constraints related to HOQs. Another limitation, similar to other agility studies, which facilitate decision making among agility metrics, was that the metrics were more industry-specific and less inclusive. Practical implications: A strong practical advantage for the application of the methodology over directly choosing agility metrics without linking them is that through the methodology, the right metrics were selected that match organization’s core values and marketing objectives. While metrics may ostensibly seem unrelated or inappropriate, they actually contributed to the right areas where there were gaps between the current and desired level of agility. It would otherwise be impossible to choose the right metrics without a structured methodology. Originality/value: This paper proposes a novel methodology for achieving organizational agility. By utilizing and linking several tools such as BSC, fuzzy TOPSIS, and quality function deployment (QFD), the proposed approach enables organizations to identify the most appropriate agile attributes, agile enablers, and subsequently agile improvement paths
Ponticola hircaniaensis Zarei & Esmaeili & Kovačić & Schliewen & Abbasi 2022, sp. nov.
No full textPonticola hircaniaensis sp. nov. English name: Hyrcanian goby (Figs. 5–6, Table 4) Synonyms Ponticola gorlap (Iljin, 1949): Zarei et al. 2021: 1272, table 2 (partim: Kaboudval Stream) Holotype. ZM-CBSU S101-6, male, 76.9 + 21.6 mm; Iran: Golestan prov.: Kaboudval stream, 36°53‘11.0“N 54°53‘37.8“E; F. Zarei, 27 August 2021. Paratypes. ZM-CBSU S099-1 to S099-12, 7 males, 5 females, 52.8 + 14.0–80.8 + 20.4 mm; Y. Bakhshi, Z. Ganjali & A. Jouladeh-Roudbar, 28 August 2017.—ZM-CBSU S100-1 to S100-4, 4 males, 49.8 + 13.1–95.9 + 24.1 mm; F. Zarei & Y. Bakhshi, 31 August 2019.—ZM-CBSU S101-1 to S101-5 & S101-7 to S101-15, 9 males, 5 females, 54.9 + 15.0–91.3 + 26.0 mm; F. Zarei, 27 August 2021. All paratypes were collected from Iran, Golestan prov., Kaboudval Stream, 36°53’11.0”N 54°53’37.8”E. Additional material. ZM-CBSU S099, 29 specimens, 21.8–62.7 mm SL; Y. Bakhshi, Z. Ganjali & A. Jouladeh-Roudbar, 28 August 2017.—ZM-CBSU S100, 26 specimens, 27.5–47.8 mm SL; F. Zarei & Y. Bakhshi, 31 August 2019.—ZM-CBSU S101, 9 specimens, 45.0– 50.2 mm SL; F. Zarei, 27 August 2021. All additional material was collected from Iran, Golestan prov., Kaboudval Stream. ......continued on the next page ......continued on the next page Material used in the molecular genetic analysis. Mitochondrial COI: molecular IDs: P2776–P2778 (ZMCBSU P2776 to P2778), P162 (ZM-CBSU P162), 3432 (ZM-CBSU S101-2, paratype), 3433–3440 (ZM-CBSU S101-19 to S101-26), 3441 (ZM-CBSU S101-7, paratype), 3443 (ZM-CBSU S101-9, paratype), 3444 (ZM-CBSU S101-12, paratype), 16 specimens (GenBank accession numbers: MW393596 – MW393598, and ON166711 – ON166723).—Nuclear S7: molecular IDs: 3432 (ZM-CBSU S101-2, paratype), 3438 (ZM-CBSU S101-24), 3435 (ZM-CBSU S101-21), 3443 (ZM-CBSU S101-9, paratype), 4 specimens (GenBank accession numbers: ON186768 – ON186771). All from Iran, Golestan prov., Kaboudval Stream, 36°53’11.0”N 54°53’37.8”E, F. Zarei & Y. Bakhshi, 31 August 2019 & 27 August 2021. Material used in the otolith analysis. ZM-CBSU K18, K21, K24 & K28, S101-21, S101-26, 12/19–12/22, 12/26–12/31, 12/33–12/34, and 12/37–12/39, 21 specimens, 49.24–78.44 mm SL; Iran: Golestan prov., Kaboudval Stream, 36°53’11.0”N 54°53’37.8”E; F. Zarei & Y. Bakhshi, 31 August 2019. Diagnosis. Ponticola hircaniaensis sp. nov. is distinguished from all other congeneric species in the Caspian Sea basin by the following combination of characters: D2 I/14–I/16 (usually I/15), A I/10–I/12 (usually I/11), LL 52–59; lower jaw slightly, if at all, prognathous; head and body yellowish brown, showing a reticulate brown pattern on a yellow background, D1 with a marginal bright orangish-yellow band and a dark anterior spot, P base upper part with a distinct dark brown stripe; D1 third spine length 13.4–18.3 % SL, D2 spine length 11.1–13.8 % of SL, caudalpeduncle length and depth 16.4–20.1 % and 11.1–12.8 % of SL, respectively, head depth at nape and eye 70.9–81.0 % and 52.5–66.0 % of HL, respectively. Dorsal rim of sagittal otolith with a broad concavity in the middle, dorsal depression absent or indistinct, SuL/SuH and SuH/OH ratio 1.47–1.82 and 0.34–0.40, respectively. Description. All morphometric values in the text are presented as holotype first and paratypes, if different, in parentheses. General morphology (Fig. 5): Body proportions are given in Table 4. Body moderately elongate, its depth at pelvic-fin origin 3.94 (3.78–4.78) in SL, at anal-fin origin 4.94 (4.82–5.52) in SL, laterally compressed posteriorly, with caudal peduncle moderately deep, caudal-peduncle depth 0.67 (0.57–0.76) of caudal-peduncle length. Head large, the length 3.32 (3.16–3.51) in SL, width 4.12 (3.62–4.48) in SL, its depth 4.11 (4.01–4.85) in SL and 1.0 (0.82–1.05) of width. Postorbital profile steep. Snout short, oblique, convex, longer than eye, its length 1.41 (1.13– 1.62) of eye diameter, 3.64 (3.11–3.91) in head length. Anterior nostril short, erect flared tube, the rim posteriorly elevated; posterior nostril pore-like, with more or less raised rim. Eyes dorsolateral, more lateral than dorsal, small, eye diameter is 5.15 (4.02–5.32) in head length, orbit slightly elevated. Interorbital wide, 1.44 (1.28–2.58) in eye diameter. Mouth directed obliquely upwards, lower jaw little if at all prognathous, upper lip widened in middle and swollen, angle of jaws below pupil. Cheek deep and prominent. Dentary in both jaws with conical teeth in outermost and innermost rows, irregular rows of smaller teeth in-between. Branchiostegal membranes fused to isthmus along the entire lateral margin of the isthmus, from immediately anterior to pectoral margin, gill openings restricted to pectoral-fin base. Fins. D1 VI; D2 I/14–16 (holotype I/14; paratypes: I/14:8, I/15:18, I/16:4) (last bifid); A I/10–I/12 (holotype I/11; paratypes: I/10:2, I/11:21, I/12:7) (last bifid); P 17–20 (holotype, left side: 18; paratypes, left side: 17:2, 18:22, 19:5, 20:1), V I/5 + 5/I. Morphometric characters are given in Table 4. D 1 dorsal profile horizontal, lower than the highest part of D2 dorsal profile. First to fourth D1 spines becoming progressively longer, fifth D1 spine shorter than the second. First D1 spine almost as long as D2 spine. D2 highest in the middle. D1 and D2 connected by interdorsal membrane, interdorsal space between D1 VI and D2 I narrow. D2 originates slightly in front of vertical to anus. A originates below 4th to 5th branched rays of D2. A with last ray origin below origin of penultimate ray or below origin of last ray of D2. The D2 (except for large specimens) and A rays not reaching backwards the base of uppermost and lowermost caudal-fin rays, respectively. C rounded, shorter than head length. P reaches beyond vertical of D2 origin. P rays all branched, the uppermost rays not free from the membrane. V disc complete, rounded, originates slightly anterior of vertical through D1 origin, not reaching anus or rarely extending almost to anterior anus origin, the variability present in both sexes. V all rays branched. V anterior membrane present, lateral lobes of anterior membrane well developed and with pointed tips. Squamation. Nape, predorsal area, upper 1/3 of opercle, posterior part of breast, and abdomen all covered with cycloid scales, and the rest of the body covered with ctenoid scales. Scales on caudal peduncle slightly enlarged. Cheek naked. Base of pectoral fin naked. LL 52–59 (holotype, left side: 55; paratypes, left side: 52:1, 53:7, 54:5, 55:3, 56:4, 57:8, 58:1, 59:1), TR 16–20 (holotype, left side: 19; paratypes, left side: 16:4, 17:5, 18:15, 19:5, 20:1), PD 19–23 (holotype 21; paratypes: 19:2, 20:8, 21:12, 22:7, 23:1). Lateral line system (Fig. 6). Cephalic canals. AOC, POC, and PC present. AOC with a single, unified interorbital section, carrying 12 pores: a pair of posterior nasal pores σ, single interorbital pores λ and κ, and paired ω, α, β, ρ; pores σ and ρ terminal, pore λ directly on the canal, pores κ and ω behind the canal, and pores α and β lateral of the canal. POC paired, each with two pores: θ and τ. PC paired, each side with three pores: γ, δ and ε. Head sensory papillae. Rows with range of number of sensory papillae in parentheses. Preorbital: median series in five rows: r 1 (6–9) and r 2 (7–8) as oblique rows opposite posterior nostril, extending over the canal section between λ and σ; midline of snout anterior of λ free of neuromasts; s 1 (7–11) and s 2 (8–11), as transverse rows anterior to σ; s 3 (13–18) as cluster anterior and lateral of s 2 , reaching near to upper lip; lateral series in four rows, each doubled; c 2 oblique between the anterior and posterior nostrils, with lower section (7–9) often longer than upper (4–6); c 1 (10–14) transversal lateral of anterior nostril and dorsal of c 2 (10–13); c 2 and c 1 (7–9) in longitudinal and oblique rows, respectively; c 2 ventral of c 1 , c 1 ventral of c 2 and dorsal of d 1 (22–26), oblique and posteriorly close to suborbital row 1. Suborbital: seven transversal (1–7) and two longitudinal (b, d) rows on cheek, rows 1–4 (1: 21–29, 2: 20–27, 3: 22–31, 4: 31–36) before longitudinal row b, long, ventrally extending to level of d, dorsally reaching close to eye except row 2 and sometimes row 3; rows 1 and 2 above and anterior to rear edge of jaws, row 3 right above or slightly behind the jaws angle; row 5 and 6 divided by b in short superior (5s: 9– 11, 6s: 7–9) and longer inferior (5i: 16–20, 6i: 12–18) sections; 5i ending above longitudinal row d, 6i passing behind row d, ending slightly below its level; 5i and 6i not confluent with each other; row 7 short (2–6), immediately anterior of pore α; row b (21–27) anteriorly reaching to below posterior end of pupil; row d long, not reaching 6i posteriorly, often distinctly divided and separable in two slightly overlapping parts, the anterior supralabial row d 1 oblique, following the border of the upper lip and reaching below the anterior origin of d 2 (21–24), the posterior row d 2 longitudinal on cheek; row d 1 anteriorly passing row 1. Asymmetrical variant specimens (30% of the material examined and only on the left side of the head) were found with one additional row before row b, i.e., five transverse suborbital rows before row b and eight transverse suborbital rows in total, or with four transverse suborbital rows before row b, but followed by one additional row below row b, i.e., three transverse rows below row b. Preoperculo-mandibular: not shown in Figure 4. Three rows, e, i and f; external row e distinctly divided at articulation of lower jaws in anterior mandibular (e 1 : 51–63) and posterior preopercular (e 2 : 47–59) sections; anterior and posterior sections of internal row i (i 1 , i 2 ) are continuous (93–123), their separation at articulation of lower jaws is indistinct; both usually with additional papillae and i 1 continuous with the symphyseal row f (10–14). Oculoscapular: eight transversal (z, q, u, trp, y, as 1 –as 3 ) and four longitudinal (x 1 , x 2 , la 2 –la 3 ) rows including the axillary series; x 1 long (17–20), parallel to and exceeding AOC, reaching to trp (5–6); x 2 (6–9) in elongation of x 1 , above posterior fourth of opercle, parallel to and exceeding POC; z (7–9) in elongation of PC, ventrally reaching close to but not exceeding pore γ; y (7–8) immediately behind τ and below x 2 ; three short transverse rows in oculoscapular groove between ρ and θ; q (4–5) anterior most, close to ρ, extending ventrally of the oculoscapular groove and sometimes with one or two papillae dorsal of ρ; posterior most trp close to θ, extending dorsally and passing upwards the level of x 1 ; between q and trp a third transverse row named here row u (3–4) considering its position despite row being transverse; transversal axillary rows as 1 -as 3 long (as 1 : 12–18, as 2 : 13–17, as 3 : 12–15); longitudinal axillary series represented by two rows (la 2 : 2–4, la 3 : 2–3). Opercular: three rows, one transversal (ot: 38–52), sometimes divided in two parts, and two longitudinal (os: 17–23, oi: 14–19) rows. Anterior-dorsal (occipital): five rows, two transversal (n and o) and three longitudinal (g, m and h); n (9–11) behind pore ω of AOC; rows o (6–10) widely separated; row g (7–12) posterior of o, not reaching row o anteriorly; m (5–8) almost parallel to g, behind and below it; h anterior to origin of first dorsal fin (D1), divided in two sections (h 1 : 5–8, h 2 : 3–6). Colouration. No distinct sexual dichromatism, or colouration differences in hybrids is evident on the specimens. In life: head and body yellowish brown; several large dark brown saddles on back below the dorsal fins and on the caudal peduncle; flanks covered with many dark brown spots and row of irregular and elongated dark blotches along the midline, all forming a reticulate pattern on a yellow background; cheek with brown reticulations or mottlings, and with a short brown longitudinal stripe starting below eye and going backwards about half way to preopercle; upper lip with reticulate patterns or mottles; P base with reticulate patterns, upper part with a distinct dark brown stripe. Breast, abdomen, and fins greyish. D1 with two to three brown horizontal bands, and a bright orangish-yellow horizontal band along upper edge of I–V interradial membrane, progressively narrowing posteriorly; upper anterior part of D1 with a dark oblique spot on I–II interradial membrane below the marginal band. D2 with three distinct longitudinal rows of yellowish-brown spots on proximal part, distal half with numerous small spots on the sides of the rays. Anal fin without any distinct band or mark. P rays yellowish. P and C with several concentric narrow rows of yellowish-brown spots, concentrated near base of fin. D2, A, and C with whitish fringe along the edge. Preserved specimens: background colour of the preserved specimens less yellowish; brown saddles on back below D1 and D2 and on the caudal peduncle; flanks with row of large dark blotches along the midline. Head and body with less pronounced reticulate patterns. Cheek with a longitudinal dark brown stripe. Fins dark grey. D1 with a white band across upper edge, two to three horizontal dark bands, and a dark oblique spot between I–II. P base with a dark strip on the upper part. Horizontal rows and brown spots on all fins less distinct than in live specimens. Otolith. (Figs. 1 & 7a–d, Table 5). The five specimens with the new species haplotype were not examined for their otoliths since they were (i) fixed in 10% formaldehyde solution (formaldehyde causes decalcification and degradation of otoliths) for subsequent morphological analyses, (ii) included as paratypes (4 of 5; see material examined). Therefore, otoliths from a total of 21 specimens from the Kaboudval Stream (including several specimens with the gorlap haplotype) were examined using light microscopy and digital photographs. All otoliths were similar in general morphology, thus, four of these otoliths (Fig. 7 a-d) were selected randomly for SEM imaging, morphometric measurements, and description. The otoliths have a parallelogram shape, with marked preventral and posterodorsal projections. The otolith length to height (OL/OH) ratio is 1.22–1.39; the dorsal rim with a broad concavity in the middle, smooth; predorsal angle orthogonal; posterodorsal projection highly positioned, broad, long, pointed or blunt, and slightly bent outwards. The anterior rim usually lacks incision, or is sometimes incised at or slightly above the level of ostium, inclined at 72.30–84.29° (β). Posterior rim almost parallel to the anterior rim or a little less oblique, inclined at 101.31–104.86° (γ), with a concavity (incision or notch) below the posterodorsal projection at or slightly below the level of cauda. Angle of preventral to posterodorsal traverse 24.36–34.14° (δ). Ventral rim horizontal and smooth; preventral projection usually long, sometimes short, pointed or blunt; posteroventral angle usually orthogonal. Sulcus centrally positioned, sole-shaped, anteriorly inclined at 10.22–19.06° (α), very deep with developed ostial lobe. Sulcus moderately long, and very wide; the ratio of sulcus length to height (SuL/SuH) 1.47–1.82. The sulcus height to otolith height (SuH/OH) ratio is 0.34–0.40. Subcaudal iugum present, short (usually 1/3 cauda length), slender, below the anterior part of the cauda. Ventral furrow running with a moderate distance to ventral rim, curved upwards anteriorly to or slightly below the level of the ostial apex and turning upwards to the level of the caudal tip or slightly below it. Dorsal depression indistinct or absent. Otolith variables and shape indices are provided in Table 5. ......continued on the next page Sexual dimorphism. Sexes can be distinguished externally by the shape of the urogenital papilla, which is conical in males with pointed posterior edge, and wider, trapezoid and with villous posterior edge in females. Males grow to a larger size (up to 120.0 mm total length vs. 101.2 mm for female maximum recorded total length). All morphometric and meristic characteristics are overlapping, males however, (i) tend to have a deeper cheek (18.02–24.37 vs. 16.92–19.61% of Hl), (ii) are dominated by individual (14 of 21) with 15 branched rays in the second dorsal fin [vs. 14 branched rays in females (6 of 10)], and (iii) show a larger range of pectoral fin rays (17–20 vs. 18–19). Etymology. Named for Hyrcania, the Greek name for the south Caspian region where the species occurs. Distribution and conservation. Ponticola hircaniaensis sp. nov. is known only from its type locality, located 1 km south of the city of Aliabad-e-Katul (Figs. 8–9). Its small population is confined to a single area (extent of occurrence <2 km 2) above the Zarrin Gol Dam (IUCN criteria B1 and Ba for critically endangered species) (Fig. 9). Habitat fragmentation by the dam is likely to block gene flow, resulting in decline of genetic diversity, and possibly increases competition for spawning territories and resources, and increases hybridization with P. gorlap. Moreover, according to our field observations, there is a decline in quality of habitat at Kaboudval due to excessive grazing, erosion, and human effects [IUCN criterion Bb(iii)]. In addition, Pseudorasbora parva (Temminck & Schlegel, 1846) and Gambusia holbrooki Girard, 1859, two of the most successful invasive fish species in the world with negative impacts on native fish species, have established populations at Kaboudval. For example, high densities of P. parva have severe and significant impacts on native trophic food webs, resulting in overlap with native fishes trophic niches, increased egg predation, and transmission of the novel fungal fish pathogen Sphaerothecum destruens, which is responsible for the decline of many native fish populations (Andreou et al. 2012). Based on the extremely small area of endemism threatened by negative anthropogenic impact we suggest that P. hircaniaensis sp. nov. should be classified as Critically Endangered (CR) species, fulfilling geographic range criteria (extant of occurrence combined with two more conditions) for this category, according to the IUCN (2012) red list categories. Ecology. Ponticola hircaniaensis sp. nov. is an exclusively freshwater species, restricted to a very shallow foothill stream (0.1–0.3 m depth, 1–2 m width) with slow current (Fig. 9). The bottom is muddy-sandy or composed of cobbles and boulders, pebbles and gravel, and the banks are vegetated. The collecting site was at the altitude of 196 m a.s.l., and 79 km inland from the Caspian Sea. Syntopic fish species were Alburnoides tabarestanensis MousaviSabet, Anvarifar & Azizi, 2015, Gambusia holbrooki Girard, 1859, Hemiculter leucisculus (Basilewsky, 1855), and Pseudorasbora parva (Temminck & Schlegel, 1846).Published as part of Zarei, Fatah, Esmaeili, Hamid Reza, Kovačić, Marcelo, Schliewen, Ulrich K. & Abbasi, Keyvan, 2022, Ponticola hircaniaensis sp. nov., a new and critically endangered gobiid species (Teleostei: Gobiidae) from the southern Caspian Sea basin, pp. 401-430 in Zootaxa 5154 (4) on pages 408-421, DOI: 10.11646/zootaxa.5154.4.1, http://zenodo.org/record/665112
On the buckling load estimation of grid-stiffened composite conical shells using vibration correlation technique
No full textIn this paper, the vibration correlation technique (VCT) has been used as a nondestructive method for predicting the buckling load of grid-stiffened composite conical shells. This technique is capable of predicting the buckling load of structures without reaching failure point through modal testing. The grid-stiffened composite conical shell has been fabricated using the filament winding process. To perform the experiment, the fundamental natural frequency of the specimen is measured under stepped axial compression loading. The procedure is followed up without actually reaching the instability point when the structure collapses and is no longer usable. A finite element model has been built using ABAQUS software considering the effect of geometric imperfection in order to determine the correlation between natural frequency and applied compressive load. A comparison of the experimental and numerical approaches indicated that the difference between numerical buckling loads and those obtained via the VCT is negligible. Moreover, the VCT has provided a reliable estimate of the buckling load, especially when the maximum applied load is greater than 67% of the experimental buckling load
Statistical mechanics of the “Chinese restaurant” process: lack of self-averaging, anomalous finite-size effects, and condensation
No full textThe Pitman-Yor, or Chinese restaurant process, is a stochastic process that generates distributions following a power law with exponents lower than 2, as found in numerous physical, biological, technological, and social systems. We discuss its rich behavior with the tools and viewpoint of statistical mechanics. We show that this process invariably gives rise to a condensation, i.e., a distribution dominated by a finite number of classes. We also evaluate thoroughly the finite-size effects, finding that the lack of stationary state and self-averaging of the process creates realization-dependent cutoffs and behavior of the distributions with no equivalent in other statistical mechanical models
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