161 research outputs found
Pore size distribution and supercritical hydrogen adsorption in activated carbon fibers
Pore size distributions (PSD) and supercritical H_2 isotherms have been measured for two activated carbon fiber (ACF) samples. The surface area and the PSD both depend on the degree of activation to which the ACF has been exposed. The low-surface-area ACF has a narrow PSD centered at 0.5 nm, while the high-surface-area ACF has a broad distribution of pore widths between 0.5 and 2 nm. The H_2 adsorption enthalpy in the zero-coverage limit depends on the relative abundance of the smallest pores relative to the larger pores. Measurements of the H_2 isosteric adsorption enthalpy indicate the presence of energy heterogeneity in both ACF samples. Additional measurements on a microporous, coconut-derived activated carbon are presented for reference
The Bio-Politics of Population Control and Sex Selective Abortion in China and India
China and India, two countries with skewed sex ratios in favor of males, have introduced a wide range of policies over the past few decades to prevent couples from deselecting daughters, including criminalizing sex-selective abortion through legal jurisdiction. This article aims to analyze how such policies are situated within the bio-politics of population control and how some of the outcomes reflect each government’s inadequacy in addressing the social dynamics around abortion decision making and the social, physical, and psychological effects on women’s wellbeing in the face of criminalization of sex-selective abortion. The analysis finds that overall, the criminalization of sex selection has not been successful in these two countries. Further, the broader economic, social, and cultural dynamics which produce bias against females must be a part of the strategy to combat sex selection, rather than a narrow criminalization of abortion which endangers women’s access to safe reproductive health services and their social, physical, and psychological wellbeing
Adsorption and melting of hydrogen in potassium-intercalated graphite
Volumetric adsorption and quasielastic neutron scattering are used to study the diffusion and thermodynamics of sorbed H_2 in the graphite intercalation compound KC24. A sorption enthalpy of 8.5 kJ/mol at zero coverage is determined from H_2 adsorption isotherms. From measurements of total elastic-neutron-scattering intensity as a function of temperature, a melting transition of the H_2 adsorbate is observed at 35 K for KC_(24)(H_2)_1. Quasielastic-neutron-scattering (QENS) spectra reveal distinct slow- and fast-H_2-diffusion processes which exist simultaneously at temperatures above the transition point. The temperature dependence of the characteristic diffusion times follows an Arrhenius relation tau=tau_0 exp(E_a/T), where tau_0^(fast)=1.0±0.1 ps, tau_0^(slow)=21±2 ps, E_a^(fast)=156±5 K, and E_a^(slow)=189±5 K. The fast-diffusion process is attributable to individual motions of H_2 molecules in a static potassium structure, and the slow-diffusion process could be attributable to fluctuations in H_2 particle density correlated with jumps of potassium atoms. The QENS spectra at low Q are used to discuss the dimensionality of the diffusion process
Determination of Arsenic, Mercury and Barium in herbarium mount paper using dynamic ultrasound-assisted extraction prior to atomic fluorescence and absorption spectrometry
A dynamic ultrasound-assisted extraction method using Atomic Absorption and Atomic Flourescence spectrometers as detectors was developed to analyse mercury, arsenic and barium from herbarium mount paper originating from the herbarium collection of the National Museum of Wales. The variables influencing extraction were optimised by a multivariate approach. The optimal conditions were found to be 1% HNO3 extractant solution used at a flow rate of 1 mL min-1. The duty cycle and amplitude of the ultrasonic probe was found to be 50% in both cases with an ultrasound power of 400 W. The optimal distance between the probe and the top face of the extraction chamber was found to be 0 cm. Under these conditions the time required for complete extraction of the three analytes was 25 min. Cold vapour and hydride generation coupled to atomic fluorescence spectrometry was utilized to determine mercury and arsenic, respectively. The chemical and instrumental conditions were optimized to provide detection limits of 0.01ng g-1 and 1.25 ng g-1 for mercury and arsenic, respectively. Barium was determined by graphite-furnace atomic absorption spectrometry, with a detection limit of 25 ng g-1. By using 0.5 g of sample, the concentrations of the target analytes varied for the different types of paper and ranged between 0.4–2.55 µg g-1 for Ba, 0.035–10.47 µg g-1 for As and 0.0046–2.37 µg g-1 for Hg
Organometallic iridium(III) anticancer complexes with new mechanisms of action: NCI-60 screening, mitochondrial targeting, and apoptosis
Platinum complexes related to cisplatin, cis-[PtCl2(NH3)2], are successful anticancer drugs; however, other transition metal complexes offer potential for combating cisplatin resistance, decreasing side effects, and widening the spectrum of activity. Organometallic half-sandwich iridium (IrIII) complexes [Ir(Cpx)(XY)Cl]+/0 (Cpx = biphenyltetramethylcyclopentadienyl and XY = phenanthroline (1), bipyridine (2), or phenylpyridine (3)) all hydrolyze rapidly, forming monofunctional G adducts on DNA with additional intercalation of the phenyl substituents on the Cpx ring. In comparison, highly potent complex 4 (Cpx = phenyltetramethylcyclopentadienyl and XY = N,N-dimethylphenylazopyridine) does not hydrolyze. All show higher potency toward A2780 human ovarian cancer cells compared to cisplatin, with 1, 3, and 4 also demonstrating higher potency in the National Cancer Institute (NCI) NCI-60 cell-line screen. Use of the NCI COMPARE algorithm (which predicts mechanisms of action (MoAs) for emerging anticancer compounds by correlating NCI-60 patterns of sensitivity) shows that the MoA of these IrIII complexes has no correlation to cisplatin (or oxaliplatin), with 3 and 4 emerging as particularly novel compounds. Those findings by COMPARE were experimentally probed by transmission electron microscopy (TEM) of A2780 cells exposed to 1, showing mitochondrial swelling and activation of apoptosis after 24 h. Significant changes in mitochondrial membrane polarization were detected by flow cytometry, and the potency of the complexes was enhanced ca. 5× by co-administration with a low concentration (5 μM) of the γ-glutamyl cysteine synthetase inhibitor L-buthionine sulfoximine (L-BSO). These studies reveal potential polypharmacology of organometallic IrIII complexes, with MoA and cell selectivity governed by structural changes in the chelating ligands
Parent perceptions of the quality of life of pet dogs living with neuro-typically developing and neuro-atypically developing children: an exploratory study
There is growing scientific and societal recognition of the role that pet dogs can play in healthy development of children; both those who are neuro-typically developing and those who live with a neuro-developmental disorder, such as autism or attention deficit hyperactivity disorder. However, little attention has been paid to how living with children positively and negatively affects quality of life of a pet dog. In this exploratory study we conducted semi-structured interviews with parents of neuro-typically developing children (n = 18) and those with a neuro-developmental disorder (n = 18) who owned a pet dog, until no new factors were identified. Living with children brought potentially positive benefits to the dog’s life including: imposition of a routine, participation in recreational activities and the development of a strong bond between the child and the dog. The importance of maintaining a routine was particularly prevalent in families with children with neuro-developmental disorders. Potential negative factors included having to cope with child meltdowns and tantrums, over stimulation from child visitors, harsh contact and rough and tumble play with the child. The regularity and intensity of meltdowns and tantrums was particularly evident in responses from parents with children with a neuro-developmental disorder. However, child visitors and rough play and contact were mentioned similarly across the groups. Protective factors included having a safe haven for the dog to escape to, parent’s awareness of stress signs and child education in dog-interaction. Parents were also asked to complete a stress response scale to provide an initial quantitative comparison of stress responses between dogs living with the two family-types. Parents with neuro-typically developing children more frequently observed their dog rapidly running away from a situation and less frequently observed their dog widening their eyes, than parents with children with a neuro-developmental disorder. We propose the development of a stress audit based on the findings reported here, to prevent potential dangerous situations, which may lead to dog bites and dog relinquishment and allow owners to maximise the benefits of dog ownership
Sex Selective Abortion, Neoliberal Patriarchy and Structural Violence in India
This article explores sex selective abortion (SSA) as a form of structural violence within the broader notion of women’s ‘protection’ in contemporary India. While SSA tends to be framed more generally within ethical and choice-based frameworks around abortion access and reproductive ‘rights’, and specifically in India around preference for sons as a discriminatory, cultural, technological misogyny, this article argues that sex selective abortion in India needs to be understood as an outcome of broader systemic economic, political and social processes. The deepening of neoliberal values through state policies has impacted significantly on social relations, shaping SSA as a manifestation of structural violence. State-driven policies in India reflect a neoliberal governmentality through state patriarchy that is implicit within the neoliberal developmental, governmental and capitalist paradigm of contemporary India. This article argues that SSA is structurally produced and therefore cannot be remedied through awareness-raising strategies such as beti bachao or financial inclusion as a means to ‘protect’ or ‘save the girl child’. Indeed, it is neoliberal economic forces that actively, though seemingly inadvertently, promote anti-women, sex selective abortion as a reproductive strategy, which is then disciplined through neoliberal governmentality. This highlights SSA as a form of gendered and structural, rather than discriminatory, violence
Risks and opportunities of open-source generative AI
Applications of Generative AI (Gen AI) are expected to revolutionize a number of different areas, ranging from science & medicine to education. The potential for these seismic changes has triggered a lively debate about the potential risks of the technology, and resulted in calls for tighter regulation, in particular from some of the major tech companies who are leading in AI development. This regulation is likely to put at risk the budding field of open-source generative AI. Using a three-stage framework for Gen AI development (near, mid and long-term), we analyze the risks and opportunities of open-source generative AI models with similar capabilities to the ones currently available (near to mid-term) and with greater capabilities (long-term). We argue that, overall, the benefits of open-source Gen AI outweigh its risks. As such, we encourage the open sourcing of models, training and evaluation data, and provide a set of recommendations and best practices for managing risks associated with open-source generative AI
A systematic review and meta-analysis of lifestyle and body mass index predictors of successful assisted reproductive technologies
Objective: Lifestyle (smoking, drinking alcohol) and body mass index (BMI) predictors of successful outcomes in assisted reproductive technology (ART) treatments were examined in this meta-analysis.
Method: A bibliographic search was undertaken using six databases. The review was informed by PRISMA/MOOSE guidelines. Meta analytic data were analysed using random effects models.
Results: We included 77 studies examining effects of BMI, smoking and drinking alcohol. Patients with a BMI25 OR 1.219 (95% CI:1.128–1.319, z 4.971, p<.001; I2 53.779%, p .001). Non-smokers were significantly more likely to achieve a LB or pregnancy than smokers OR 1.457 (95% CI:1.228–1.727, z 4.324, p<.001; I2 51.883; p .001). Meta-regression revealed the number of embryos transferred significantly moderated the effects of smoking on ART outcomes, and there was a trend indicating primary infertility and high BMI were also significant moderators. The evidence for drinking alcohol was inconclusive due to the small number of studies.
Conclusions: This meta-analysis confirms that ART treatment success can be predicted with life-style factors. Further, non-smokers’ relative odds of pregnancy/live birth increase as more embryos were transferred but there was a trend that the odds of pregnancy/live birth decrease with primary infertility and high BMI
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