2,314 research outputs found
A Dual-Channel Spectrometer Based on 1mm-Thick SDDs for the Study of Nuclear Beta Decays
No full textWe present the ASPECT-BET project developing a dual-channel SDD-based spectrometer designed to achieve high-precision measurements of beta decays across a broad energy range (spanning from 10 keV to 1 MeV). The adoption of SDDs in electron spectroscopy represents a relatively novel approach, with promising preliminary results already observed in the TRISTAN project, which focuses on accurate beta spectroscopy of Tritium decay. The primary objective of ASPECTBET
is to extend the research, including more energetic radioactive sources to study allowed and forbidden nuclear beta decays. To achieve this goal, we have incorporated larger (8 mm diameter) and thicker (1 mm-thick) detectors to enhance the absorption capability of the
spectrometer, and a CSA featuring a larger feedback capacitance. Furthermore, by utilizing two SDDs arranged one in front of the other, post-acquisition data processing can be applied to eliminate partial energy depositions in detectors caused by undesirable effects such as electron backscattering or escape of characteristic X-rays. An assessment of the energy resolution achieved at the Mn-Kα (5.9 keV)
fluorescence line, obtained by exposing the spectrometer to a 55Fe calibration source, is presented. A FWHM below 200 eV is achieved under conditions of a 1 μs peaking time and cooling at -23 °C, indicating the potential suitability of the spectrometer for high-energy beta decay
studies
Proactive Safety Evaluation of Infrastructure Designs Using Driving Simulation
No full textIn this research, the usefulness of driving simulation for studying the effects of road designs on human driving behaviour before these road designs are implemented in real life is explored. The research consists of three studies designed to address important safety issues related to human driving behaviour regarding merging on motorways, separation of express and local lanes on motorways, and horizontal curves situated in a two-way rural road. The experimentation was conducted by allowing participants to drive in a virtually created road environment in a medium fidelity driving simulator at IMOB. The results obtained from the three studies conclude that driving simulation is an economical, effective, efficient, and a safe tool for evaluation of road designs prior to their construction. Evaluating road designs in the design phase will considerably improve the level of safety of road designs. It can also highlight the possible flaws in the road design (if any) and help road designers with decision making in the road design process. The results obtained from this research promote the use of the driving simulator for evaluation of road designs so that possible social and economic losses that might result due to an unsafe road design can be avoided.Higher Education Commission (HEC) Pakista
Proactive Safety Evaluation of Infrastructure Designs Using Driving Simulation
No full textIn this research, the usefulness of driving simulation for studying the effects of road designs on human driving behaviour before these road designs are implemented in real life is explored. The research consists of three studies designed to address important safety issues related to human driving behaviour regarding merging on motorways, separation of express and local lanes on motorways, and horizontal curves situated in a two-way rural road. The experimentation was conducted by allowing participants to drive in a virtually created road environment in a medium fidelity driving simulator at IMOB. The results obtained from the three studies conclude that driving simulation is an economical, effective, efficient, and a safe tool for evaluation of road designs prior to their construction. Evaluating road designs in the design phase will considerably improve the level of safety of road designs. It can also highlight the possible flaws in the road design (if any) and help road designers with decision making in the road design process. The results obtained from this research promote the use of the driving simulator for evaluation of road designs so that possible social and economic losses that might result due to an unsafe road design can be avoided.Higher Education Commission (HEC) Pakista
Genetic variability and host specialization in Alternaria alternata colonizing Solanaceous crops in Sudan
No full textEarly blight disease caused by Alternaria sp. is one of the most devastating diseases of
Solanaceous crops widely distributed in Sudan. The aim of this study was to determine the
genetic variation among different Alternaria isolates recovered from different Solanaceae
crops showing typical symptoms of early blight disease. Infected leaves of tomato, potato,
eggplant and pepper were collected from different geographical zones in Sudan. The recovered
fungal isolates were identified to the genus level based on cultural and morphological
characteristics. Five representative isolates were sent to the CABI Bioscience, U.K. for confirmation.
The genetic relationship among the isolates was determined using the amplified
fragments length polymorphism (AFLP) technique and the generated data were used to
create similarity matrices using the PAST 3.01 software package. Dendrograms were constructed
based on Jaccard’s similarity coefficients. A total of 70 fungal isolates was recovered
from the tested plants and all of them showed morphological characteristics typical
of Alternaria spp. The conidia appeared in multiple-branched chains with spore sizes in
the range of 2.38−13.09 μm × 12.30−43.63 μm. Therefore, the isolates were identified as
Alternaria alternata (Fr.) Keissl. The identification was then confirmed by CABI.AFLPbased
dendrogram which revealed five clusters with a significant cophenetic correlation
coefficient (r = 0.834) between the dendrogram and the original similarity matrix irrespective
of their geographical origins. Eighteen (75%) of the Alternaria isolated from tomato
leaves were clustered together in cluster I and five isolates formed two separate clusters,
viz. cluster IV (T-Kh5 and T-H1) and cluster V (T-H4 and T-Med2). The remaining isolate,
T-Am5, grouped with one of the potato isolates in cluster III. The other isolates which were
recovered from potato, pepper and eggplants were all separated from the tomato isolates
in the largest cluster
Gq Protein-Coupled Membrane-Initiated Estrogen Signaling Rapidly Excites Corticotropin-Releasing Hormone Neurons in the Hypothalamic Paraventricular Nucleus in Female Mice
No full textCRH neurons in the hypothalamic paraventricular nucleus (PVN) play a central role in regulating the hypothalamus-pituitary-adrenal (HPA) axis and are directly influenced by 17β-estradiol (E2). Although compelling evidence has suggested the existence of membrane-associated estrogen receptors (mERs) in hypothalamic and other central nervous system neurons, it remains unknown whether E2 impacts CRH neuronal excitability through this mechanism. The purpose of the current study is to examine the existence and function of mER signaling in PVN CRH neurons. Whole-cell recordings were made from CRH neurons identified by Alexa Fluor 594 labeling and post hoc immunostaining in ovariectomized female mice. E2 (100nM) rapidly suppressed the M-current (a voltage-dependent K(+) current) and potentiated glutamatergic excitatory postsynaptic currents. The putative Gq-coupled mER (Gq-mER) characterized in hypothalamic proopiomelanocortin neurons initiates a phospholipase C-protein kinase C-protein kinase A pathway; therefore, we examined the involvement of this pathway using selective inhibitors. Indeed, the ER antagonist ICI 182780 and inhibitors of Gq-phospholipase C-protein kinase C-protein kinase A blocked E2's actions, suggesting dependence on the Gq-mER. Furthermore, STX, a selective ligand for the Gq-mER, mimicked E2's actions. Finally, to examine the in vivo effect of Gq-mER activation, E2 or STX injection increased c-fos expression in CRH neurons in the PVN, suggesting CRH neuronal activation. This corresponded to an increase in plasma corticosterone. We conclude that the Gq-mER plays a critical role in the rapid regulation of CRH neuronal activity and the HPA axis. Our findings provide a potential underlying mechanism for E2's involvement in the pathophysiology of HPA-associated mood disorders.Peer reviewe
Intermittent Fasting Promotes Fat Loss with Lean Mass Retention, Increased Hypothalamic Norepinephrine Content, and Increased Neuropeptide Y Gene Expression in Diet-Induced Obese Male Mice
No full textClinical studies indicate alternate day, intermittent fasting (IMF) protocols result in meaningful weight loss in obese individuals. To further understand the mechanisms sustaining weight loss by IMF, we investigated the metabolic and neural alterations of IMF in obese mice. Male C57/BL6 mice were fed a high-fat diet (HFD; 45% fat) ad libitum for 8 weeks to promote an obese phenotype. Mice were divided into 4 groups and either maintained on ad libitum HFD (HFD), received alternate day access to HFD (IMF- HFD), switched to ad libitum low fat diet (LFD; 10% fat), or received IMF of LFD (IMF- LFD). After 4 weeks, IMF-HFD (~13%) and IMF-LFD (~18%) had significantly lower body weights than HFD. Body fat was also lower (~40-52%) in all diet interventions. Lean mass was increased in the IMF-LFD (~12-13%) compared with HFD and IMF-HFD groups. Oral glucose tolerance AUC was lower in the IMF-HFD (~50%), whereas insulin tolerance AUC was reduced in all diet interventions (~22-42%). HPLC measurements of hypothalamic tissue homogenates indicated higher (~55-60%) norepinephrine (NE) content in the anterior regions of the medial hypothalamus of IMF compared with ad libitum fed groups, whereas NE content was higher (~19-32%) in posterior regions in the IMF-LFD group only. Relative gene expression of Npy in the arcuate nucleus was increased (~65-75%) in IMF groups. Our novel findings indicate that intermittent fasting produces alterations in hypothalamic NE and NPY, suggesting an involvement in the counter regulatory processes of short-term weight loss are associated with an IMF dietary strategy.Peer reviewe
Family altruism and incentives
No full textThe author builds on the altruistic model of the family, to explore the strategic interaction between altruistic parents, and selfish children, when children's efforts are endogenous. If there is uncertainty about the amount of income the children will realize, and if parents have imperfect information, the children have an incentive to exert little effort, and to rely on their parent's altruistically motivated transfers. Because of this, parents face a tradeoff between the insurance that bequests implicitly provide their children, and the disincentive to work prompted by their altruism. The author shows that if parents can credibly commit to a pattern of transfers, they will choose not to compensate children in bad outcomes, as much as predicted by the standard (no uncertainty, no asymmetric information) dynastic model of the family. Alternatively, parents may choose to forgo any insurance, and offer a fixed level of bequest, to elicit greater effort from their children. The optimal transfers structure that the author derives, reconciles the predictions of the altruistic family model, with much of the existing evidence on inter-generational transfers, which suggests that parents compensate only partially, or not at all, for earnings differentials among their children. Moreover, the author shows that Ricardian equivalence holds in this setup, except when non-negativity constraints are binding.Economic Theory&Research,Environmental Economics&Policies,Health Economics&Finance,Educational Sciences,Safety Nets and Transfers
Agha Shahid Ali, 18th Annual ODU Literary Festival
No full textPoet Agha Shahid Ali teaches in the M.F.A. Creative Writing Program at the University of Massachusetts, Amherst. His six collections of poetry include A Nostalgist’s Map of America, The Half Inch Himalayas, A Walk Through the Yellow Pages and The Beloved Witness: Selected Poems. He has also translated The Rebel’s Silhouette, a selection of poems by Faiz Ahmed Faiz as well as the author of T. S. Eliot as Editor. His poems appear regularly in journals such as Antioch Review, Chelsea, Denver Quarterly, Field, Grand Street, Paris Review Poetry, TriQuarterly and Yale Review. He has won fellowships from the Pennsylvania Council on the Arts, the Ingram-Merril Foundation, the Bread Loaf Writers’ Conference and the New York Foundation for the Art. His recent — as yet uncollected — poems focus on the current turmoil in Kashmir, where he is from originally and where he spends his summers
Intercomparison and Assessment of Stand-Alone and Wavelet-Coupled Machine Learning Models for Simulating Rainfall-Runoff Process in Four Basins of Pothohar Region, Pakistan
No full textThe science of hydrological modeling has continuously evolved under the influence of rapid advancements in software and hardware technologies. Starting from simple rational formulae for estimating peak discharge and developing into sophisticated univariate predictive models, accurate conversion of rainfall into runoff and the assessment of inherent uncertainty has been a prime focus for researchers. Therefore, alternative data-driven methods have gained widespread attention in hydrology. Moreover, scientists often couple conventional machine learning models with data pre-processing techniques, i.e., wavelet transformation (WT), to enhance modelling accuracy. In this context, this research work attempts to explore the latent linkage between rainfall and runoff in Pothohar region of Pakistan by developing a novel linkage of five streamline techniques of machine learning, including single decision tree (SDT), decision tree forest (DTF), tree boost (TB), multilayer perceptron (MLP), and gene expression modeling (GEP), with a more sophisticated variant of WT, i.e., maximal overlap discrete wavelet transformation (MODWT), for boundary correction of the transformed components of timeseries data. This study also implements these machine learning models in a stand-alone mode for a more comprehensive comparative analysis of performances. Furthermore, the study uses a combined-basin approach that divides Pothohar region into two basins to compensate for the complex topographic division of the study area. The results indicate that MODWT-based DTF outperformed other stand-alone and hybrid models in terms of modeling accuracy. In the first scenario, considering the Bunha-Kahan River basin, MODWT-DTF yielded the highest NSE (0.86) and the lowest RMSE (220.45 mm) and R2 (0.92 at lag order 3 (Lo3)) when transformed with daubechies4 (db4) at level three. While in the Soan-Haro River basin, MODWT-DTF produced the highest accuracy modeling at lag order 4 (Lo4) (NSE = 0.88, RMSE = 21.72 m(3)/s, and R2 = 0.91). The highly accurate performance of 3- and 4-days lagged models reflects the temporal consistency in hydrological response of the study area. The comparison of simple and hybrid model performance indicates up to a 55% increase in modeling accuracy due to data pre-processing with wavelet transformation
Multi-channel customer management: A case study in Egypt
No full textChannel management is one CRM systems component much influenced by the behaviour of customers in relation to the implementation and use of channel management CRM component. The consumers’ behaviours, preferences, perceptions and expectations are crucial for the implementation and use of channel management. Customers’ contact with the organization’s multi-channels can occur at several touch points through out customer lifecycle. Customers’ behaviours may be differentiated according to the individual or micro level, but it might also differ at an ecological or macro level of analysis (Ramaseshan et al., 2006). In this paper the author has conducted a case study in Egypt to analyze customers’ behaviours at a macro level and customers channel choices, through out the customer lifecycle. The author has used a Structurational Analysis model (Ali and Brooks, 2008) to identify the cultural factors (Ali, et al. 2008) that influence the multi-channel customer management in Egypt
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