COVID-19 Close Contact Management: An Evolution of Operations Harnessing the Digital Edge.

Singapore, like many other nations globally, had to contend with significant caseloads arising from the Coronavirus disease (COVID-19) pandemic. This paper focuses on using technology as an intervention for pandemic management. With scant scientific evidence on effective medications and vaccinations (i.

Monitoring rhinoceroses in Namibia's private custodianship properties.

Routinely censusing rhinoceros' populations is central to their conservation and protection from illegal killing. In Namibia, both white () and black () rhinoceros occur on private land, in the latter case under a custodianship program of the Namibian Ministry of Environment and Tourism (MET). Black rhinoceros custodian landowners are responsible for the protection of the rhinoceroses on their land and are required to report regularly to the MET.

Testing 'Proportion of Females Calving' as an indicator for population-level reproductive performance for black rhinoceros ().

The proportion of females calving (PFC) each year has been employed as an indicator of population reproductive performance in ungulates, especially for species that breed annually, because it requires less detailed population data than inter-birthing intervals and age at first reproduction. For asynchronous breeders with inter-birthing intervals longer than a year such as megaherbivores, however, it is unclear how much annual variation in PFC is expected and whether false signals of density feedback or environmental influence might result from analyzing PFC data. We used census data from a well studied, closed, expanding population of black rhinoceros () to study annual variation in PFC over 22 years.

Forest bat population dynamics over 14 years at a climate refuge: Effects of timber harvesting and weather extremes.

Long-term data are needed to explore the interaction of weather extremes with habitat alteration; in particular, can 'refugia' buffer population dynamics against climate change and are they robust to disturbances such as timber harvesting. Because forest bats are good indicators of ecosystem health, we used 14 years (1999-2012) of mark-recapture data from a suite of small tree-hollow roosting bats to estimate survival, abundance and body condition in harvested and unharvested forest and over extreme El Niño and La Niña weather events in southeastern Australia. Trapping was replicated within an experimental forest, located in a climate refuge, with different timber harvesting treatments.

Effects of age and sex ratios on offspring recruitment rates in translocated black rhinoceros.

Success of animal translocations depends on improving postrelease demographic rates toward establishment and subsequent growth of released populations. Short-term metrics for evaluating translocation success and its drivers, like postrelease survival and fecundity, are unlikely to represent longer-term outcomes. We used information theory to investigate 25 years of data on black rhinoceros (Diceros bicornis) translocations.

Feedforward Coordinate Control of a Robotic Cell Injection Catheter.

Remote and robotically actuated catheters are the stepping-stones toward autonomous catheters, where complex intravascular procedures may be performed with minimal intervention from a physician. This article proposes a concept for the positional, feedforward control of a robotically actuated cell injection catheter used for the injection of myogenic or undifferentiated stem cells into the myocardial infarct boundary zones of the left ventricle. The prototype for the catheter system was built upon a needle-based catheter with a single degree of deflection, a 3-D printed handle combined with actuators, and the Arduino microcontroller platform.

Experimental evidence for homeostatic sex allocation after sex-biased reintroductions.

First principles predict negative frequency-dependent sex allocation, but it is unproven in field studies and seldom considered, despite far-reaching consequences for theory and practice in population genetics and dynamics as well as animal ecology and behaviour. Twenty-four years of rhinoceros calving after 45 reintroductions across southern Africa provide the first in situ experimental evidence that unbalanced operational sex ratios predicted offspring sex and offspring sex ratios. Our understanding of population dynamics, especially reintroduction and invasion biology, will be significantly impacted by these findings.

Quantifying the demographic cost of human-related mortality to a raptor population.

Raptors are exposed to a wide variety of human-related mortality agents, and yet population-level effects are rarely quantified. Doing so requires modeling vital rates in the context of species life-history, behavior, and population dynamics theory. In this paper, we explore the details of such an analysis by focusing on the demography of a resident, tree-nesting population of golden eagles (Aquila chrysaetos) in the vicinity of an extensive (142 km2) windfarm in California.

Conceptual Design and Procedure for an Autonomous Intramyocardial Injection Catheter.

This article discusses existing catheter systems and proposes a conceptual design and procedure for an autonomous cell injection catheter for the purpose of transferring committed myogenic or undifferentiated stem cells into the infarct boundary zones of the left ventricle. Operation of existing catheters used for cell delivery is far from optimal. Commercial injection catheters available are handheld devices operated manually by means of tip deflection and torque capabilities.

Designed α-sheet peptides inhibit amyloid formation by targeting toxic oligomers.

Previous studies suggest that the toxic soluble-oligomeric form of different amyloid proteins share a common backbone conformation, but the amorphous nature of this oligomer prevents its structural characterization by experiment. Based on molecular dynamics simulations we proposed that toxic intermediates of different amyloid proteins adopt a common, nonstandard secondary structure, called α-sheet. Here we report the experimental characterization of peptides designed to be complementary to the α-sheet conformation observed in the simulations.

Skeletal myoblast transplantation on gene expression profiles of insulin signaling pathway and mitochondrial biogenesis and function in skeletal muscle.

Aim: The study aims to investigate the gene expression profiling of insulin signaling pathway and mitochondrial biogenesis and function in the skeletal muscle of KK mice.

Methods: KK mice were divided into the following groups: KK control group, basal medium (M199) only; KK fibroblast group, with human fibroblast transplantation; KK myoblast group, with human skeletal myoblast transplantation. C57BL mice received hSkM transplantation as a normal control.

Translocations as experiments in the ecological resilience of an asocial mega-herbivore.

Species translocations are remarkable experiments in evolutionary ecology, and increasingly critical to biodiversity conservation. Elaborate socio-ecological hypotheses for translocation success, based on theoretical fitness relationships, are untested and lead to complex uncertainty rather than parsimonious solutions. We used an extraordinary 89 reintroduction and 102 restocking events releasing 682 black rhinoceros (Diceros bicornis) to 81 reserves in southern Africa (1981-2005) to test the influence of interacting socio-ecological and individual characters on post-release survival.

The relationship between water bridges and the polyproline II conformation: a large-scale analysis of molecular dynamics simulations and crystal structures.

It has been suggested that denatured proteins are predisposed toward the left-handed polyproline II (P(II)) conformation. One possible source of P(II) stability in the denatured state is water bridges. Water bridges are networks of water molecules that link nearby hydrogen bond acceptors and/or donors on proteins.

Atraumatic fractures in heart failure.

Osteoporosis and heart failure are 2 highly prevalent conditions, particularly among the elderly, both of which account for significant morbidity and mortality. In this review, we describe the epidemiology of osteoporosis and osteoporotic-related fractures in persons with heart failure. A review of the current literature regarding shared risk factors for heart failure and osteoporosis is presented, and potential common pathophysiologic mechanisms for these disorders are discussed.

Liposome-based vascular endothelial growth factor-165 transfection with skeletal myoblast for treatment of ischaemic limb disease.

The study aims to use cholesterol (Chol) + DOTAP liposome (CD liposome) based human vascular endothelial growth factor-165 (VEGF(165)) gene transfer into skeletal myoblasts (SkMs) for treatment of acute hind limb ischaemia in a rabbit model. The feasibility and efficacy of CD liposome mediated gene transfer with rabbit SkMs were characterized using plasmid carrying enhanced green fluorescent protein (pEGFP) and assessed by flow cytometry. After optimization, SkMs were transfected with CD lipoplexes carrying plasmid-VEGF(165) (CD-pVEGF(165)) and transplanted into rabbit ischaemic limb.

Angiomyogenesis using liposome based vascular endothelial growth factor-165 transfection with skeletal myoblast for cardiac repair.

We aim to investigate the feasibility and efficacy of cholesterol (Chol)+DOTAP liposome (CD liposome) based human vascular endothelial growth factor-165 (hVEGF(165)) gene transfer into human skeletal myoblasts (hSkM) for cardiac repair. The feasibility and efficacy of CD liposome for gene transfer with hSkM was characterized using plasmid carrying enhanced green fluorescent protein (pEGFP). Based on the optimized transfection procedure, hSkM were transfected with CD lipoplexes carrying plasmid-hVEGF(165) (CD-phVEGF(165)).

Nonviral vector-based gene transfection of primary human skeletal myoblasts.

Low-level transgene efficiency is one of the main obstacles in ex vivo nonviral vector-mediated gene transfer into primary human skeletal myoblasts (hSkMs). We optimized the cholesterol:N-[1-(2, 3-dioleoyloxy)propyl]-N, N, N-trimethylammonium methylsulfate liposome (CD liposome) and 22-kDa polyethylenimine (PEI22)- and 25-kDa polyethylenimine (PEI25)-mediated transfection of primary hSkMs for angiogenic gene delivery. We found that transfection efficiency and cell viability of three nonviral vectors were cell passage dependent: early cell passages of hSkMs had higher transfection efficiencies with poor cell viabilities, whereas later cell passages of hSkMs had lower transfection efficiencies with better cell viabilities.

Myoblast-based cardiac repair: xenomyoblast versus allomyoblast transplantation.

Objective: We sought to investigate immune cell kinetics in relation to skeletal myoblast survival and heart function improvement after nonautologous skeletal myoblast transplantation in a rat model of myocardial infarction.

Methods: One week after myocardial infarction, 208 Wistar rats were grouped into group 1 (n = 24, receiving 150 muL of medium only), group 2 (n = 24, receiving 150 muL of medium and cyclosporine [INN: ciclosporin]), group 3 (n = 40, human skeletal myoblast transplantation), group 4 (n = 40, human skeletal myoblast transplantation with cyclosporine treatment), group 5 (n = 40, rat skeletal myoblast transplantation), and group 6 (n = 40, rat skeletal myoblast transplantation with cyclosporine treatment). The hearts were harvested at 10 minutes and 1, 4, 7, and 28 days after cell transplantation.

Transplantation of nanoparticle transfected skeletal myoblasts overexpressing vascular endothelial growth factor-165 for cardiac repair.

Background: We investigated the feasibility and efficacy of polyethylenimine (PEI) based human vascular endothelial growth factor-165 (hVEGF165) gene transfer into human skeletal myoblasts (HSM) for cell based delivery to the infarcted myocardium.

Methods And Results: Based on optimized transfection procedure using enhanced green fluorescent protein (pEGFP), HSM were transfected with plasmid-hVEGF165 (phVEGF165) carried by PEI (PEI-phVEGF165) nanoparticles. The transfected HSM were characterized for transfection and expression of hVEGF165 in vitro and transplanted into rat heart model of acute myocardial infarction (AMI): group-1=DMEM injection, group-2= HSM transplantation, group-3= PEI-phVEGF165-transfected HSM (PEI-phVEGF165 myoblast) transplantation.

Mutagenesis data in the automated prediction of transmembrane helix dimers.

We present a molecular modeling protocol that selects modeled protein structures based on experimental mutagenesis results. The computed effect of a point mutation should be consistent with its experimental effect for correct models; mutations that do not affect protein stability and function should not affect the computed energy of a correct model while destabilizing mutations should have unfavorable computed energies. On the other hand, an incorrect model will likely display computed energies that are inconsistent with experimental results.

E(z), a depth-dependent potential for assessing the energies of insertion of amino acid side-chains into membranes: derivation and applications to determining the orientation of transmembrane and interfacial helices.

We have developed an empirical residue-based potential (E(z) potential) for protein insertion in lipid membranes. Propensities for occurrence as a function of depth in the bilayer were calculated for the individual amino acid types from their distribution in known structures of helical membrane proteins. The propensities were then fit to continuous curves and converted to a potential using a reverse-Boltzman relationship.

Improved angiogenic response in pig heart following ischaemic injury using human skeletal myoblast simultaneously expressing VEGF165 and angiopoietin-1.

Objective: To achieve angiogenic interaction between VEGF(165) and angiopoietin-1 (Ang-1) using a novel adenoviral bicistronic vector (Ad-Bic) encoding the two factors and delivered ex vivo using sex-mismatched human skeletal myoblasts.

Methods And Results: A myocardial infarction model was developed in 29 female pigs; randomised into four groups: DMEM (group-1, n=6); Adenovirus null (Ad-null) vector-myoblast (group-2, n=5); Ad-Ang-1 myoblast (group 3, n=7) and Ad-Bic-myoblast (group-4, n=11). Three weeks later, 5 ml DMEM without myoblasts or containing 3 x 10(8) myoblasts carrying lac-z gene and transduced with Ad-null, Ad-Ang-1 or Ad-Bic were injected intra-myocardially in and around the infarct.

Myoblast transplantation on the beating heart.

Cellular cardiomyoplasty using various types of donor cells is now validated by a large number of experimental studies. We report a case of cellular cardiomyoplasty performed on a beating heart using autologous skeletal myoblasts, thus combining the efficacy of both procedures. Approximately 2.

Reversal of myocardial injury using genetically modulated human skeletal myoblasts in a rodent cryoinjured heart model.

Background: We hypothesized that combination therapy using human myoblasts and VEGF165 will lead to better prognosis in a failing heart.

Methods: Forty-eight female Wistar rats with cryoinjured hearts were randomized into non-treated normal (group-1, n=12), DMEM injected (group-2, n=10), myoblast-transplanted (group-3, n=12) and myoblast-hVEGF(165) (group-4, n=14). Ten days after cryoinjury, 200 microl DMEM containing 3x10(6) cells or without cells was injected into the injured myocardium.

In vitro functional assessment of human skeletal myoblasts after transduction with adenoviral bicistronic vector carrying human VEGF165 and angiopoietin-1.

Objectives: We report in vitro functional assessment of human skeletal myoblasts with adenoviral bicistronic vector carrying human vascular endothelial growth factor-165 (hVEGF165) and angiopoietin-1 (Ang-1).

Methods: Myoblasts were assessed for their purity by desmin expression. A replication incompetent adenoviral bicistronic vector (Ad-Bic) carrying both hVEGF165 and Ang-1 was used for transduction of myoblasts.