32 research outputs found
Population studies of a commercially fished bivalve mercenaria mercenaria (L), in Southampton Water
No full textThe hard shell clam Mercenaria mercenaria (L.) is a long-lived animal tolerating wide environmental variations. The animal is an important constituent of the macrobenthic fauna in Southampton Water. A study was made of various aspects of the population in relation to absence of cooling water discharge caused by closure of Marchwood power station, increased fishing activities and the frequent failure of settlement in recent years. The littoral population at 12 sites was sampled in two successive winters. The highest density of clams was at Netley and the lowest at Royal Pier, with actively growing and reproducing populations extending to Solent Breezes and Lee-on-Solent in the eastern Solent. The total stock estimated for littoral sites above Hamble Spit has shown a reduction of about 50% since 1970. The population at present is dominated by large and old individuals originating from settlements in 1971, 1972, 1973 and 1976. These year classes and a recent settlement in 1984 seem to coincide with low river flow during August, September and October of each year. The annual production of littoral Mercenaria populations at both Marchwood and Lee-on-Solent approximated to 3gm-2yr.-1. Although Mercenaria dominates the biomass of the benthic fauna, energetically its role in the ecosystem has been diminished in recent years as a result of change in the population structure towards larger/older individuals. Growth in Mercenaria was analyzed according to the Logistic, the Gompertz and the Monomolecular models. The Gompertz provides an accurate model of ontogenic growth in Mercenaria. Highest predictive growth rate in shell length was found in littoral population at Solent Breezes, Hamble Spit, Weston and Netley. Maximum growth rates in shell length were achieved during the 2nd and 3rd years, whereas maximum growth rates in flesh weight were recorded during the 4th and 5th years, indicating that during the early stages and before gonad maturation a greater proportion of energy is directed to formation of shell rather than in flesh. Monthly gamete counts at Marchwood and Lee-on-Solent permitted assessment of the reproductive cycle, and the consequences of gamete production on variation of growth at both sites were discussed. It appears that at Marchwood a greater proportion of available energy is devoted to gamete production and less to somatic growth than at Lee-on-Solent. The gamete counting also revealed that the peak of spawning occurred at the end of summer and during autumn, this result was supporting data obtained by weekly monitoring of larvae. Results suggest that Mercenaria is capable of spawning at 16oC, which is a lower temperature than that reported in earlier works, indicating a physiological adaptation to local conditions. Growth, survival and environmental factors affecting abundance of planktonic larvae over an 8 days period were studied. It appears that larvae remain in the plankton for about 15 days, at summer temperature. The 12 hours survey of vertical distribution provides evidence that larvae are retained within Southampton Water through behavioural regulation during different stages of the tide. The distribution, seasonal growth and survival of spat throughout the estuary, were investigated. First settlement of the spat in 1984 took place in the latter part of August. The population is seen as stock in decline largely resulting from overfishing and failure of spat settlement in recent years.</p
A taxonomic Study on Trees and Shrubs of El Nour Natural Forest Reserve, Blue Nile State-Sudan
No full textThe study was carried out at El Nour Natural Forest Reserve, Blue Nile
State, during the years 2007-2008. The objectives were to document the flora of
El Nour Natural Forest Reserve through collection, identification and
classification of the woody species (trees and shrubs) in the forest. The collected
species were revised for botanical names, synonyms and vernacular names and
their description were updated to the recent available literature. High quality
digital images were used in the illustration of the prevailing flora in support and
completion of the taxonomic description.
The study identified 54 plant species that belong to 36 genera, 17 families
and 3 subfamilies (19 dicotelydonae and 1 monocotelydonae).
The family Ochnaceae has been reported for the first time in the forest and
is represented by one species (Ochna afzelii R.Brenan. ex Oliver) which is known
locally by Lesan El Kalb.
The update names for some families and subfamilies were used in this
study as follows:
Capparaceae instead of Capparidaceae and Fabaceae instead of
Leguminosae. At the subfamilies level, Mimosoideae, Caesalpinioideae and
Papilionoideae were used instead of Mimosaceae, Caesalpinaceae and
Papilionaceae respectively.
The subfamily Mimosoideae showed the highest species and genera
frequency. The species density and composition is variable within the forest due
to variation in soil type, topography, overgrazing and illegal cutting of the local
inhabitants within and around the forest. Common uses of the identified species
were extracted from the local knowledge and literature
New organic PVC photo-stabilizers derived from synthesised novel coumarine moieties
No full textNew four coumarin derivatives (9–12) compounds have been successfully synthesized from the reaction of salicyaldehyde and ethylacetoacetate yielding 3-acetyl coumarine, which on further treatment with bromine/chloroform gave 3-(2-Bromoacetyl) coumarine. Substituted 4-(Benzylidene-amino)-]triazole-3-thiol reacted with 3-(2-Bromoacetyl) coumarine to give 3-sulfanyl-acetyl-4-(Benzylidene-amino)-triazol related coumarin derivatives. The newly synthesized products were characterized with FTIR, 1H and 13C NMR, and energy dispersive X-ray spectra to confirm their chemical structures. All above used techniques demonstrated the formation of target products with high percentage of purity. The synthesised compounds (9–12) have been investigated as organic additives to protect poly(vinyl chloride) (PVC) from photo-degradation at (λmax = 313 nm) and irradiation period 300 h in the atmosphere. The stabilizing efficiencies of blended PVC films were examined by detecting changes in their infrared spectra, weight, and average molecular weight viscosity. A light microscope, atomic force microscopy, and a scanning electron micrograph were all used to examine the surface morphology of the films. The additives enhanced considerable resistance of films against irradiation and the polymeric surface was significantly smoother in the presence of the coumarine derivatives compared with the blank film. The strongest photo-stabilization effect was seen in coumarine derivative (12) containing 2-hydroxy naphthol the most effective as UV absorber, free radical scavenger, and quencher. This phenomenon appears to allow energy to be transported through resonant aryl rings and various intersystem crossover mechanisms
Coating Readily Available Yet Thermally Resistant Surfaces with 3D Silver Nanowire Scaffolds: A Step toward Efficient Heater Fabrication
No full textIn this study, we synthesized and characterized a 3D network of silver nanowires (AgNWs), employing the polyol approach in ethylene glycol (EG) as the reductant and polyvinylpyrrolidone (PVP) as the structure-directing agent for the growth of AgNWs to design inexpensive, timely responsive AgNWs-based heaters with different substrates. Data obtained from a field emission scanning electron microscope (FESEM) revealed that the average diameter of the synthesized AgNWs was 22 nm, and the average length was 28 µm. UV-visible absorption spectroscopy showed that AgNWs developed in a very pure phase. We investigated the impact of substrate type on the heating dissipation performance by depositing AgNW thin film over three chosen substrates made from readily available materials. The findings indicated that the AgNW-based heater with the wood substrate had the lowest response time of 21 s, the highest thermal resistance of 352.59 °C·cm2/W, and a steady temperature of 135 °C at a low bias voltage of 5 V compared to cement (95 s, 297.77 °C·cm2/W, and 120 °C) and glass (120 s, 270.25 °C·cm2/W, and 110 °C)
A schematic diagram highlighting our current understanding of the differential effects of PF and SF PAMAM dendrimers on EGFR-ERK1/2-p38MAPK signaling and apoptosis via an oxidative-dependent mechanism in HEK 293 cells.
No full text<p>Data from the present study and from Akhtar et al [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132215#pone.0132215.ref036" target="_blank">36</a>] are summarized. We previously showed that SF stimulated basal EGFR phosphorylation via an oxidative-stress dependent mechanism and also enhanced EGF-ligand induced activation (Akhtar et al, 2013). In the present study, we showed that PF also inhibits basal EGFR phosphorylation via an oxidative stress mechanism as well as EGF-ligand induced activation of EGFR. SF and PF both induced apoptosis via an oxidative-stress/ROS dependent mechanism. AG1478, a selective inhibitor of EGFR tyrosine kinase, inhibited the stimulatory effects of SF and also induced apoptosis in HEK 293 cells (Akhtar et al, 2013). Antioxidants inhibiting formation of reactive oxygen species/oxidative stress were able to prevent PF and SF induced modulation of basal EGFR activation and dendrimer-induced apoptosis.</p
Exploring the Impact of Social Media on Attaining HbA1c Targets in Individuals with Type 2 Diabetes Mellitus in Iraq: A Cross-Sectional Study
No full textObjectives: Type 2 diabetes mellitus (T2DM) is a persistent metabolic illness causing elevated glucose levels due to insulin resistance. Social media has been found to positively impact diabetes management by boosting motivation, adherence, emotional support, and sharing evidence-based information, thereby enhancing patients’ glycemic control efforts and achieving HbA1c targets. Primarily to examine the influence of social media within a random sample Iraqi population of T2DM patients on the control of diabetes, as measured by HbA1c levels. Methods: A multicentric cross-sectional study involves patients diagnosed with T2DM recruited between December 30, 2019 and November 8, 2023. Patients diagnosed with T2DM, who visited the outpatient clinic at least twice during the study period, were included. The sample size comprised 2921 patients. Various social media platforms available including, Facebook, WhatsApp, Instagram, Telegram, X (formerly known as Twitter), and Viber, were reported. Results: The study involves 2921 participants with a mean age of 53.3 years, 56% of them successfully reached their HbA1c target within a mean of 18.17 months. A significant correlation was found between achieving the target and using social media ( P = .0001), with a shorter average duration among social media users compared to non-users. A family history of diabetes also significantly correlated with achieving the desired outcome, suggesting a probable positive correlation ( P = .019). Conclusion: The study reveals a significant association between social media usage and glycemic control, introducing the importance of technology-based interventions in enhancing diabetes self-management, highlighting the relationships between social media engagement and HbA1c target achievement
Utilization of Metal Oxides Nanoparticles in Modulating Polyvinyl Chloride Films to Resist Ultraviolet Light
No full textModified poly(vinyl chloride) (PVC) films with organic groups (amino group from ethylene di-amine (en) and a suitable aromatic aldehyde from benzaldehyde (BEN)) were synthesized by casting using tetrahydrofuran (THF) solvent. The films were doped with four metal oxides nanoparticles (NPs), namely: CuO, Cr2O3, TiO2, and Co2O3, to improve the anti-photodegradation property. The films were irradiated with ultraviolet light and the resulting damage was assessed using different analytical and morphological techniques. These techniques included FTIR, 1H-NMR, and 13C-NMR spectroscopies that were used to examine the chemical structure, while another set of devices, namely optical microscope, scanning electronic microscopy (SEM), and atomic force microscope (AFM) were used to examine the morphology. In order to confirm that modified PVC acts as PVC photostabilizers, the roughness factor (Rq) was measured for the irradiated PVC films. The average Rq for irradiated blank PVC, modified PVC, modified PVC/CuO NPs, modified PVC/TiO2 NPs, modified PVC/Co2O3 NPs, and modified PVC/Cr2O3 NPs films were 368.3, 76.1, 62.6, 53.2, 45.8, and 33.8, respectively. Infrared spectroscopy and weight loss determination indicated that the films incorporated with additives showed less damage and fewer surface changes compared to the blank film. All mentioned additives acted as UV screeners against the UV light. The modified PVC/Cr2O3 NPs film showed the highest ability to resist the photo-degradation process based on the results data of FTIR spectra, weight loss, and surface morphology. In addition, after 300 h of irradiation, the weight percentage of modified PVC/Cr2O3 NPs film was 0.911 in contrast to the blank PVC, 2.896. Among the tested films, modified PVC/Cr2O3 NPs film showed the best results
Assessing the Effects of HbA1c Reduction on Alleviating Chronic Nonspecific Low Back Pain in Prediabetic Non-obese Patients: A Non-Randomized Controlled Trial
No full textBackground: Pre-diabetes, characterized by elevated glycemic indices, poses a high risk of diabetes development, and is increasingly linked to non-specific low back pain. While mechanisms remain incompletely understood, metabolic, inflammatory, and neurological factors are implicated. Dietary interventions, including low-glycemic and anti-inflammatory diets, alongside weight management, may improve outcomes in this population. Objectives: In this non-randomized controlled trial, we aim to evaluate the influence of decreasing HbA1c levels on reducing chronic non-specific low back pain in pre-diabetic, non-obese individuals, as well as emphasizing the importance of such a study in supporting the literature. Methods: A non-randomized controlled single-blind clinical trial was conducted among 82 participants with chronic non-specific low back pain and pre-diabetes at an outpatient clinic in Baghdad from the 30th of January to the 22nd of September. The intervention methods aimed at reducing HbA1c levels to assess the reduction impact on alleviating chronic non-specific low back pain included dietary adjustments, sleep optimization, and correction of vitamins and minerals deficiencies. The follow-up process was conducted individually for each participant, with a monthly assessment over a period of six months. Results: At 12 weeks a significant decrease in chronic non-specific low back pain severity was observed in patients with lower HbA1C levels yielding a P -value of .021. Similarly, at 24 weeks there was a decline in the number of patients who reported chronic non-specific low back pain, and the association to lower HbA1C levels was significant with a p -value of .005. Conclusion: This study suggests the presence of a statistically significant association between reduction of HbA1C levels and ensuing improvement in chronic non-specific low back pain symptoms in non-obese prediabetic patients
