Do insectivorous bird communities decline on land-bridge forest islands in Peninsular Malaysia?

To assess the impact of habitat fragmentation on tropical avian communities, we sampled lowland forest birds on six land-bridge islands and two mainland forest sites in Lake Kenyir, Peninsular Malaysia using timed point counts, hypothesizing that insectivorous birds are the worst affected guild. We used an information-theoretic approach to evaluate the effects of area, isolation, primary dietary guild (omnivore, frugivore and insectivore) and their interactions in predicting species richness, abundance and diversity. Our analysis showed that a model that considered the effects of area, dietary guild and their interaction best explained observed patterns of species richness. But a model considering both area and dietary guild best explained the variation in abundance. Notably, insectivorous birds were singled out as the dietary guild most sensitive to fragmentation, followed by frugivorous and omnivorous birds and hence provide support for our hypothesis. Assemblages of insectivorous birds were clearly depauperate on anthropogenic forest islands in Lake Kenyir and are consistent with forest fragmentation studies in the Neotropics. Given their specialized foraging ecology and diversity, conservation of intact communities of insectivorous bird guilds in Malaysia will be critical for maintaining predator-prey interactions in lowland tropical forest

Blue Carbon Science, Management and Policy Across a Tropical Urban Landscape

The ability of vegetated coastal ecosystems to sequester high rates of “blue” carbon over millennial time scales has attracted the interest of national and international policy makers as a tool for climate change mitigation. Whereas focus on blue carbon conservation has been mostly on threatened rural seascapes, there is scope to consider blue carbon dynamics along highly fragmented and developed urban coastlines. The tropical city state of Singapore is used as a case study of urban blue carbon knowledge generation, how blue carbon changes over time with urban development, and how such knowledge can be integrated into urban planning alongside municipal and national climate change obligations. A systematic review of blue carbon studies in Singapore was used to support a qualitative review of Singapore’s blue carbon ecosystems, carbon budget, changes through time and urban planning and policy. Habitat loss across all blue carbon ecosystems is coarsely estimated to have resulted in the release of ∼12.6 million tonnes of carbon dioxide since the beginning of the 20th century. However, Singapore’s remaining blue carbon ecosystems still store an estimated 568,971 – 577,227 tonnes of carbon (equivalent to 2.1 million tonnes of carbon dioxide) nationally, with a small proportion of initial loss offset by habitat restoration. Carbon is now a key topic on the urban development and planning agenda, as well as nationally through Singapore’s contributions to the Paris Agreement. The experiences of Singapore show that coastal ecosystems and their blue carbon stocks can be successfully managed along an urban coastline, and can help inform blue carbon science and management along other rapidly urbanizing coastlines throughout the tropics

Acute flaccid myelitis:cause, diagnosis, and management

Acute flaccid myelitis (AFM) is a disabling, polio-like illness mainly affecting children. Outbreaks of MM have occurred across multiple global regions since 2012, and the disease appears to be caused by non-polio enterovirus infection, posing a major public health challenge. The clinical presentation of flaccid and often profound muscle weakness (which can invoke respiratory failure and other critical complications) can mimic several other acute neurological illnesses. There is no single sensitive and specific test for MM, and the diagnosis relies on identification of several important clinical, neuroimaging, and cerebrospinal fluid characteristics. Following the acute phase of AFM, patients typically have substantial residual disability and unique long-term rehabilitation needs. In this Review we describe the epidemiology, clinical features, course, and outcomes of AFM to help to guide diagnosis, management, and rehabilitation. Future research directions include further studies evaluating host and pathogen factors, including investigations into genetic, viral, and immunological features of affected patients, host-virus interactions, and investigations of targeted therapeutic approaches to improve the long-term outcomes in this population

A Nation-Wide multicenter 10-year (1999-2008) retrospective clinical epidemiological study of female breast cancer in china

<p>Abstract</p> <p>Background</p> <p>According to the very limited cancer registry, incidence and mortality rates for female breast cancer in China are regarded to be increasing especially in the metropolitan areas. Representative data on the breast cancer profile of Chinese women and its time trend over years are relatively rare. The aims of the current study are to illustrate the breast cancer profile of Chinese women in time span and to explore the current treatment approaches to female breast cancer.</p> <p>Methods</p> <p>This was a hospital-based nation-wide and multi-center retrospective study of female primary breast cancer cases. China was divided into 7 regions according to the geographic distribution; from each region, one tertiary hospital was selected. With the exception of January and February, one month was randomly selected to represent each year from year 1999 to 2008 at every hospital. All inpatient cases within the selected month were reviewed and related information was collected based on the designed case report form (CRF). The Cancer Hospital/Institute, Chinese Academy of Medical Sciences (CICAMS) was the leading hospital in this study.</p> <p>Results</p> <p>Four-thousand two-hundred and eleven cases were randomly selected from the total pool of 45,200 patients and were included in the analysis. The mean age at diagnosis was 48.7 years (s.d. = 10.5 yrs) and breast cancer peaked in age group 40-49 yrs (38.6%). The most common subtype was infiltrating ductal carcinoma (86.5%). Clinical stage I & II accounted for 60.6% of 4,211 patients. Three-thousand five-hundred and thirty-four cases had estrogen receptor (ER) and progestin receptor (PR) tests, among them, 47.9% were positive for both. Two-thousand eight-hundred and forty-nine cases had human epidermal growth factor receptor 2(HER-2) tests, 25.8% of them were HER-2 positive. Among all treatment options, surgery (96.9% (4,078/4,211)) was predominant, followed by chemotherapy (81.4% (3,428/4,211). Much less patients underwent radiotherapy (22.6% (952/4,211)) and endocrine therapy (38.0% (1,599/4,211)).</p> <p>Conclusions</p> <p>The younger age of breast cancer onset among Chinese women and more advanced tumor stages pose a great challenge. Adjuvant therapy, especially radiotherapy and endocrine therapy are of great unmet needs.</p

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI &lt;18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school&#x2;aged children and adolescents, we report thinness (BMI &lt;2 SD below the median of the WHO growth reference) and obesity (BMI &gt;2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

Core-shell structure alginate-PLGA/PLLA microparticles as a novel drug delivery system for water soluble drugs

Recent focus on particle based drug delivery systems, necessitates improved drug loading and sustainable release for water soluble drugs. Biodegradable polyesters, such as poly (lactide-co-glycolide) (PLGA) and poly (L-lactide) (PLLA), are well studied but are insufficient in terms of encapsulation efficiency for water soluble drugs and providing a stable environment for macromolecule encapsulation. Even though hydrogels could allow for higher encapsulation efficiency of water soluble drugs, they are inadequate in terms of sustained and controlled release. Hence, the aim of this study was to develop a particulate drug delivery system, with drug-loaded alginate hydrogel core, encapsulated by a hydrophobic polyester shell. This is hoped that this would improve the loading of water soluble drugs, while allowing for the release behavior to be governed by the core-shell geometry of the particulates formed. In addition, the hydrogel core is also expected to perform as a stable and friendly environment for protein encapsulation. In this work, a one-step fabrication method of core-shell microparticles by concurrent ionotropic gelation and solvent extraction was studied. The resultant microparticles fabricated, have a core-shell structure of calcium alginate, encapsulated in a shell constructed of either PLGA or PLLA. The cross-sectional morphology of particles was established via scanning electron microscopy, Raman mapping and selective dissolution of hydrogel material. The incorporation of alginate within the microparticles was shown to improve loading efficiency of model hydrophilic drug metoclopramide (MCA). Release studies also showed that the polyesteric shell functioned as a limiting barrier in drug release from a MCA loaded drug hydrogel core. Lysozyme and bovine serum albumin released from the microparticles fabricated, show similar behavior in release controlled by the polymeric shell, and also the preservation of bioactivity and protein structure post release. It is also noted that the double emulsion based fabrication method, relies on concurrent ionotropic gelation of the alginate dissolved within the internal aqueous phase of the double emulsion to form calcium alginate; and solvent evaporation to cause precipitation of the shell polymer. It is also put forward that the oil layer of the double emulsion, consisting of a hydrophobic polymer dissolved within a volatile solvent during fabrication, act as a semi-permeable membrane during fabrication and is subject to osmotic pressure forces acting from both aqueous phases. The permeability of this oil layer, the solvent extraction and polymer precipitation rate; effects of osmotic pressure; double emulsion stability; affects the particulate fabrication in terms of the cross sectional morphology, surface morphology and also subsequently release behavior. Hence, it is hoped that this new particulate drug delivery system would be valuable in areas such as delivery of macromolecules, including peptides, proteins and vaccine antigens. Consequently, these hydrogel-core hydrophobic polymer-shell microparticles would permit the improved encapsulation and release of water soluble drugs, and provide a safe environment for loading bioactive molecules.DOCTOR OF PHILOSOPHY (MSE

Corporate governance - important determinants in a changing landscape.

We investigate how corporate governance is affected by salient factors such as CEO duality, presence of at least 2 female directors and stockownership concentration using a sample of S&P 500 firms across 5 years, from 2000 to 2004. Our proxy for good corporate governance is better firm performance as measured by return on assets (ROA)

One-step fabrication of core–shell structured alginate–PLGA/PLLA microparticles as a novel drug delivery system for water soluble drugs

Current focus on particulate drug delivery entails the need for increased drug loading and sustained release of water soluble drugs. Commonly studied biodegradable polyesters, such as poly(lactide-co-glycolide) (PLGA) and poly(L-lactide) (PLLA), are lacking in terms of loading efficiency of these drugs and a stable encapsulation environment for proteins. While hydrogels could enable higher loading of hydrophilic drugs, they are limited in terms of controlled and sustained release. With this in mind, the aim was to develop microparticles with a hydrophilic drug-loaded hydrogel core encapsulated within a biodegradable polyester shell that can improve hydrophilic drug loading, while providing controlled and sustained release. Herein, we report a single step method of fabricating microparticles via a concurrent ionotropic gelation and solvent extraction. Microparticles fabricated possess a core–shell structure of alginate, encapsulated in a shell constructed of either PLGA or PLLA. The cross-sectional morphology of particles was evaluated via scanning electron microscopy, calcium alginate core dissolution, FT-IR microscopy and Raman mapping. The incorporation of alginate within PLGA or PLLA was shown to increase encapsulation efficiency of a model hydrophilic drug metoclopramide HCl (MCA). The findings showed that the shell served as a membrane in controlling the release of drugs. Such gel-core hydrophobic-shell microparticles thus allow for improved loading and release of water soluble drugs.ASTAR (Agency for Sci., Tech. and Research, S’pore

6-OHDA-Lesioned Adult Zebrafish as a Useful Parkinson’s Disease Model for Dopaminergic Neuroregeneration

Conventional mammalian models of neurodegeneration are often limited by futile axonogenesis with minimal functional recuperation of severed neurons. The emergence of zebrafish, a non-mammalian model with excellent neuroregenerative properties, may address these limitations. This study aimed to establish an adult zebrafish-based, neurotoxin-induced Parkinson’s disease (PD) model and subsequently validate the regenerative capability of dopaminergic neurons (DpN). The DpN of adult male zebrafish (Danio rerio) were lesioned by microinjecting 6-hydroxydopamine (6-OHDA) neurotoxin (6.25, 12.5, 18.75, 25, 37.5, 50 and 100 mg/kg) into the ventral diencephalon (Dn). This was facilitated by an optimised protocol that utilised 1,1′-dioctadecyl-3,3,3′,3′-tetramethyl-indocarbocyanineperchlorate (DiI) dye to precisely identify the injection site. Immunostaining was utilised to identify the number of tyrosine hydroxylase immunoreactive (TH-ir) DpN in brain regions of interest (i.e. olfactory bulb, telencephalon, preoptic area, posterior tuberculum and hypothalamus). Open tank video recordings were performed for locomotor studies. The Dn was accessed by setting the injection angle of the microinjection capillary to 60° and injection depth to 1200 μm (from the exposed brain surface). 6-OHDA (25 mg/kg) successfully ablated >85% of the Dn DpN (preoptic area, posterior tuberculum and hypothalamus) whilst maintaining a 100% survival. Locomotor analysis of 5-min recordings revealed that 6-OHDA-lesioned adult zebrafish were significantly (p < 0.0001) reduced in speed (cm/s) and distance travelled (cm). Lesioned zebrafish showed full recovery of Dn DpN 30 days post-lesion. This study had successfully developed a stable 6-OHDA-induced PD zebrafish model using a straightforward and reproducible approach. Thus, this developed teleost model poses exceptional potentials to study DpN regeneration

Identification of Autocrine Growth Factors Secreted by CHO Cells for Applications in Single-Cell Cloning Media

Chinese hamster ovary (CHO) cell lines are widely used for the expression of therapeutic recombinant proteins, including monoclonal antibodies and other biologics. For manufacturing, cells derived from a single-cell clone are typically used to ensure product consistency. Presently, fetal bovine serum (FBS) is commonly used to support low cell density cultures to obtain clonal cell populations because cells grow slowly, or even do not survive at low cell densities in protein-free media. However, regulatory authorities have discouraged the use of FBS to reduce the risk of contamination by adventitious agents from animal-derived components. In this study, we demonstrated how a complementary mass spectrometry-based shotgun proteomics strategy enabled the identification of autocrine growth factors in CHO cell-conditioned media, which has led to the development of a fully defined single-cell cloning media that is serum and animal component-free. Out of 290 secreted proteins that were identified, eight secreted growth factors were reported for the first time from CHO cell cultures. By supplementing a combination of these growth factors to protein-free basal media, single cell growth of CHO cells was improved with cloning efficiencies of up to 30%, a 2-fold improvement compared to unsupplemented basal media. Complementary effects of these autocrine growth factors with other paracrine growth factors were also demonstrated when the mixture improved cloning efficiency to 42%, similar to that for the conditioned medium