The estimation of economic benefits of urban trees using contingent valuation method in Tasik Perdana, Kuala Lumpur

Urban trees provide a multitude of tangible and intangible services which include provisionary, regulatory, as well as cultural and support services to the community. Unfortunately, to set a monetary value on these said services is challenging to say the least. Ignorance of such monetary value is unintentional and this is mainly due to the lack of awareness and the absence of monetary value of the services itself. Hence, the quality of these urban trees degrades over time as no one appreciates its monetary value. In light of this situation, a study was initiated to determine the economic benefits of the urban trees that were planted surrounding Tasik Perdana (TP) area. For this purpose, a total of 313 respondents were interviewed in the TP area using the contingent valuation method (CVM). The objective of this study was to elicit willingness to pay (WTP) for these urban trees. WTP represents the willingness of a person to pay in monetary terms to secure and sustain these urban trees. Hence, seven bid prices were used and distributed to the respondents: RM1.00, RM5.00, RM10.00, RM15.00, RM20.00, RM25.00 and RM30.00. Logit and linear regression models were applied to predict the maximum, mean, and median WTP. The study concludes that the estimated mean WTP is RM10.32 per visit and the estimated median WTP is RM10.08 per visit

Defect cluster recognition system for fabricated semiconductor wafers

The International Technology Roadmap for Semiconductors (ITRS) identifies production test data as an essential element in improving design and technology in the manufacturing process feedback loop. One of the observations made from the high-volume production test data is that dies that fail due to a systematic failure have a tendency to form certain unique patterns that manifest as defect clusters at the wafer level. Identifying and categorising such clusters is a crucial step towards manufacturing yield improvement and implementation of real-time statistical process control. Addressing the semiconductor industry's needs, this research proposes an automatic defect cluster recognition system for semiconductor wafers that achieves up to 95% accuracy (depending on the product type)

Molecular dynamics simulation of the transport of small molecules across a polymer membrane

The transport of small molecules through a polymer membrane is modeled using the computer simulation technique of molecular dynamics (MD). The transport coefficient is derived from a combination of the excess free energy and the diffusion constant. Both properties are derived from MD simulations, applied to helium and methane in polydimethylsiloxane (PDMS). The diffusional process appears to have the character of a jump diffusion for methane and less so for helium. Jumps are allowed by fluctuations of the size and shape of holes. Experimental diffusion constants are well reproduced. The excess free energies, determined by a particle insertion method, are lower by 5-7 kJ/mol than experimental values. It is shown that, as a result of a higher solubility, methane has a higher permeability constant than helium, despite its lower diffusion constant

Spin relaxation in mesoscopic superconducting Al wires

We studied the diffusion and the relaxation of the polarized quasiparticle spins in superconductors. To that end, quasiparticles of polarized spins were injected through an interface of a mesoscopic superconducting Al wire in proximity contact with an overlaid ferromagnetic Co wire in the single-domain state. The superconductivity was observed to be suppressed near the spin-injecting interface, as evidenced by the occurrence of a finite voltage for a bias current below the onset of the superconducting transition. The spin diffusion length, estimated from finite voltages over a certain length of Al wire near the interface, was almost temperature independent in the temperature range sufficiently below the superconducting transition but grew as the transition temperature was approached. This temperature dependence suggests that the relaxation of the spin polarization in the superconducting state is governed by the condensation of quasiparticles to the paired state. The spin relaxation in the superconducting state turned out to be more effective than in the normal state.Comment: 9 pages, 8 figure

Adipocyte PU.1 knockout promotes insulin sensitivity in HFD-fed obese mice.

Insulin resistance is a key feature of obesity and type 2 diabetes. PU.1 is a master transcription factor predominantly expressed in macrophages but after HFD feeding PU.1 expression is also significantly increased in adipocytes. We generated adipocyte specific PU.1 knockout mice using adiponectin cre to investigate the role of PU.1 in adipocyte biology, insulin and glucose homeostasis. In HFD-fed obese mice systemic glucose tolerance and insulin sensitivity were improved in PU.1 AKO mice and clamp studies indicated improvements in both adipose and liver insulin sensitivity. At the level of adipose tissue, macrophage infiltration and inflammation was decreased and glucose uptake was increased in PU.1 AKO mice compared with controls. While PU.1 deletion in adipocytes did not affect the gene expression of PPARg itself, we observed increased expression of PPARg target genes in eWAT from HFD fed PU.1 AKO mice compared with controls. Furthermore, we observed decreased phosphorylation at serine 273 in PU.1 AKO mice compared with fl/fl controls, indicating that PPARg is more active when PU.1 expression is reduced in adipocytes. Therefore, in obesity the increased expression of PU.1 in adipocytes modifies the adipocyte PPARg cistrome resulting in impaired glucose tolerance and insulin sensitivity

Knockdown of Ant2 Reduces Adipocyte Hypoxia And Improves Insulin Resistance in Obesity.

Decreased adipose tissue oxygen tension and increased HIF-1α expression can trigger adipose tissue inflammation and dysfunction in obesity. Our current understanding of obesity-associated decreased adipose tissue oxygen tension is mainly focused on changes in oxygen supply and angiogenesis. Here, we demonstrate that increased adipocyte O2 demand, mediated by ANT2 activity, is the dominant cause of adipocyte hypoxia. Deletion of adipocyte Ant2 improves obesity-induced intracellular adipocyte hypoxia by decreasing obesity-induced adipocyte oxygen demand, without effects on mitochondrial number or mass, or oligomycin-sensitive respiration. This led to decreased adipose tissue HIF-1α expression and inflammation with improved glucose tolerance and insulin resistance in both a preventative or therapeutic setting. Our results suggest that ANT2 may be a target for the development of insulin sensitizing drugs and that ANT2 inhibition might have clinical utility

Comparison of cluster-based and source-attribution methods for estimating transmission risk using large HIV sequence databases

Phylogenetic clustering of HIV sequences from a random sample of patients can reveal epidemiological transmission patterns, but interpretation is hampered by limited theoretical support and statistical properties of clustering analysis remain poorly understood. Alternatively, source attribution methods allow fitting of HIV transmission models and thereby quantify aspects of disease transmission. A simulation study was conducted to assess error rates of clustering methods for detecting transmission risk factors. We modeled HIV epidemics among men having sex with men and generated phylogenies comparable to those that can be obtained from HIV surveillance data in the UK. Clustering and source attribution approaches were applied to evaluate their ability to identify patient attributes as transmission risk factors. We find that commonly used methods show a misleading association between cluster size or odds of clustering and covariates that are correlated with time since infection, regardless of their influence on transmission. Clustering methods usually have higher error rates and lower sensitivity than source attribution method for identifying transmission risk factors. But neither methods provide robust estimates of transmission risk ratios. Source attribution method can alleviate drawbacks from phylogenetic clustering but formal population genetic modeling may be required to estimate quantitative transmission risk factors

Morphological Identification of Parasites Found in Ducks (Family Anatidae) Along the Mississippi River: A Parasitology Class Project

Ducks (Anatidae) can be found across much of the United States and are hosts to a variety of parasites such as nematodes, trematodes or cestodes. This study focused on identifying the species of the parasites found within ducks based on their morphological features. The morphological structures consisted of body shape, internal organs, mouthparts, and length. The ducks used in this study were legally harvested and donated by hunters from areas across the Mississippi River in Buffalo County and Trempealeau County Wisconsin. A total of 108 ducks have been analyzed for parasites. It is important to identify the types of parasites that use ducks as a host, to see if they are harmful to the ducks so that they can be better managed. Necropsy was performed on different species of ducks to extract endo and ectoparasites. The extracted parasites were stained using carmine borax so they could be viewed using microscopy. While examining the parasites under the microscope, length and width measurements were taken as well as identifying key features like hold fast organs. A published key was used as a guide to identify parasites based on the measurements and key features present. The identified parasites were compared with DNA analysis from another research group to help ensure that the identification of the parasites was correct. Finally, identifications were compared to published articles containing past research found on parasites in ducks

Combating antimicrobial resistance in Singapore: a qualitative study exploring the policy context, challenges, facilitators, and proposed strategies

Antimicrobial resistance (AMR) is a global public health threat that warrants urgent attention. However, the multifaceted nature of AMR often complicates the development and implementation of comprehensive policies. In this study, we describe the policy context and explore experts' perspectives on the challenges, facilitators, and strategies for combating AMR in Singapore. We conducted semi-structured interviews with 21 participants. Interviews were transcribed verbatim and were analyzed thematically, adopting an interpretative approach. Participants reported that the Ministry of Health (MOH) has effectively funded AMR control programs and research in all public hospitals. In addition, a preexisting One Health platform, among MOH, Agri-Food & Veterinary Authority (restructured to form the Singapore Food Agency and the Animal & Veterinary Service under NParks in April 2019), National Environment Agency, and Singapore's National Water Agency, was perceived to have facilitated the coordination and formulation of Singapore's AMR strategies. Nonetheless, participants highlighted that the success of AMR strategies is compounded by various challenges such as surveillance in private clinics, resource constraints at community-level health facilities, sub-optimal public awareness, patchy regulation on antimicrobial use in animals, and environmental contamination. This study shows that the process of planning and executing AMR policies is complicated even in a well-resourced country such as Singapore. It has also highlighted the increasing need to address the social, political, cultural, and behavioral aspects influencing AMR. Ultimately, it will be difficult to design policy interventions that cater for the needs of individuals, families, and the community, unless we understand how all these aspects interact and shape the AMR response.This research is funded through the CoSTAR-HS and SPHERiC Collaborative Center Grants from the National Medical Research Council, Singapore