Zeroing in on Net-Zero: From Soft Law to Hard Law in Corporate Climate Change Pledges

One hundred and ninety-seven nations endorsed a target of net-zero greenhouse gas (GHG) emissions by midcentury in the 2021 Glasgow Climate Pact. As countries around the world have begun to develop their plans for deep decarbonization, it has become evident that the private sector will need to deliver much of what is required for the transition to an environmentally sustainable economy. The commitment to net-zero emissions by the year 2050 has therefore cascaded to the corporate world, leading hundreds of major companies to make their own net-zero GHG pledges. What constitutes a meaningful net-zero corporate pledge, however, remains unclear—and what must be done to implement these commitments remains similarly opaque. In the absence of regulatory mandates, corporate pledges could become little more than empty optimism and may harm companies’ reputations if perceived to be greenwashing. But while governments have long dithered, other stakeholders—notably investors, consumers, NGOs, and the media—are scrutinizing corporate net-zero commitments and pressing companies to explain their climate strategies, business transformation intentions, investment plans, and reporting schedules in search of credible metrics, methodologies, and interim targets. This Article explains why the scramble to make sense of corporate net-zero emissions targets matters—arguing that these pledges may emerge as a critical point of leverage in the effort to transition toward a sustainable economy, especially in the absence of comprehensive government climate change policies. It provides an analytical framework to highlight what net-zero pledges could—and should—mean. It identifies key considerations and challenges that must be addressed in corporate GHG reduction strategies. And it documents how stakeholder demands for more robust disclosure regarding corporate net-zero pledges, as part of a broader push for more rigorous Environmental, Social, and Governance performance reporting, might establish de facto global climate change rules for major companies—creating a self-regulatory “soft law” structure of emissions reduction guidelines and incentives anticipating future regulation and government action

Pilates Mat and body composition of postmenopausal women

El objetivo de este trabajo es cuantificar, mediante Absorciometría Dual Fotónica de Rayos- X (DXA), las modificaciones de la composición corporal que la práctica de Pilates Mat produce en mujeres posmenopaúsicas de vida sedentaria. Tras un programa de ejercicios de 9 meses de duración a razón de 2 sesiones por semana de 60 minutos cada una, se observó un aumento significativo del compartimento muscular a nivel de tronco (p=0,028), abdomen (p=0,010) y brazos (p=0,042), así como una disminución significativa de la grasa de las piernas (p=0,000). La densidad mineral ósea de la columna lumbar (L2, L3 y L4) también aumentó de forma significativa. Los resultados sugieren que la práctica de Pilates Mat en mujeres posmenopaúsicas mejora su composición corporalThe aim of this study was to quantify the changes in body composition after Mat Pilates practice in postmenopausal sedentary women using Dual X-ray Photon Absorptiometry (DXA). After a 9-month exercise program consisting of 2 sessions per week of 60 minutes each, a significant increase was observed in the muscle mass of the trunk (p = 0.028), abdomen (p = 0.010) and arms (p = 0.042). A significant decrease was observed in the leg fat mass (p = 0.000). Bone mineral density of the lumbar spine (L2, L3 and L4) also increased significantly. The results suggest that the practice of Mat Pilates in postmenopausal women improves their body compositio

Simple approach to mitigate the emission wavelength instability of III-nitride μLED arrays

III-nitride semiconductors and their heterojunctions exhibit intrinsic polarization due to the asymmetry of their wurtzite structure, which determines all the fundamental properties of III-nitride optoelectronics. The intrinsic polarization-induced quantum-confined Stark effect leads to an emission wavelength shift with increasing injection current for III-nitride visible LEDs, forming an insurmountable barrier for the fabrication of a full color display. For instance, a yellow LED designed to produce yellow light emits green or blue light at an elevated current, while a green (blue) LED gives off blue (violet) light with increasing current. This color instability becomes a serious issue for a microdisplay such as the displays for augmented reality (AR)/virtual reality (VR) typically utilized at proximity to the eye, where human eyes are sensitive to a tiny change in light color. It is well-known that an optical mode wavelength for a microcavity is insensitive to injection current. In this work, we have demonstrated an approach to epitaxially integrating microLEDs (green microLEDs as an example, one of the key components for a full color microdisplay) and a microcavity. This allows the emission from the microLEDs to be coupled with the microcavity, leading to a negligible emission wavelength shift with increasing injection current. In contrast, identical microLEDs but without a microcavity show a large emission wavelength shift from 560 nm down to 510 nm, measured under identical conditions. This approach provides a simple solution to resolving the 30-year issue in the field of III-nitride optoelectronics

A simple approach to achieving ultrasmall III-nitride microlight-emitting diodes with red emission

The microdisplays for augmented reality and virtual reality require ultrasmall micro light-emitting-diodes (μLEDs) with a dimension of ≤5 μm. Furthermore, the microdisplays also need three kinds of such μLEDs each emitting red, green, and blue emission. Currently, in addition to a great challenge for achieving ultrasmall μLEDs mainly based on III-nitride semiconductors, another fundamental barrier is due to an extreme difficulty in growing III-nitride-based red LEDs. So far, there has not been any effective approach to obtain high indium content InGaN as an active region required for a red LED while maintaining high optical performance. In this paper, we have demonstrated a selective epitaxy growth approach using a template featuring microhole arrays. This allows us to not only obtain the natural formation of ultrasmall μLEDs but also achieve InGaN with enhanced indium content at an elevated growth temperature, at which it is impossible to obtain InGaN-based red LEDs on a standard planar surface. By means of this approach, we have demonstrated red μLEDs (at an emission wavelength of 642 nm) with a dimension of 2 μm, exhibiting a high luminance of 3.5 × 107 cd/m2 and a peak external quantum efficiency of 1.75% measured in a wafer form (i.e., without any packaging to enhance an extraction efficiency). In contrast, an LED grown under identical growth conditions but on a standard planar surface shows green emission at 538 nm. This highlights that our approach provides a simple solution that can address the two major challenges mentioned above

Nearly lattice-matched GaN distributed Bragg reflectors with enhanced performance

Heavy silicon-doping in GaN generally causes a rough surface and saturated conductivity, while heavily silicon-doped n++-AlGaN with ≤5% aluminum can maintain an atomically flat surface and exhibit enhanced conductivity. Given this major advantage, we propose using multiple pairs of heavily silicon-doped n++-Al0.01Ga0.99N and undoped GaN instead of widely used multiple pairs of heavily silicon-doped n++-GaN and undoped GaN for the fabrication of a lattice-matched distributed Bragg reflector (DBR) by using an electrochemical (EC) etching technique, where the lattice mismatch between Al0.01Ga0.99N and GaN can be safely ignored. By means of using the EC etching technique, the n++-layers can be converted into nanoporous (NP) layers whilst the undoped GaN remains intact, leading to a significantly high contrast in refractive index between NP-layer and undoped GaN and thus forming a DBR. Our work demonstrates that the NP-Al0.01Ga0.99N/undoped GaN-based DBR exhibits a much smoother surface, enhanced reflectivity and a wider stopband than the NP-GaN/undoped GaN-based DBR. Furthermore, the NP-Al0.01Ga0.99N/undoped GaN-based DBR sample with a large size (up to 1 mm in width) can be obtained, while a standard NP-GaN/undoped GaN-based DBR sample obtained is typically on a scale of a few 100 μm in width. Finally, a series of DBR structures with high performance, ranging from blue to dark yellow, was demonstrated by using multiple pairs of n++-Al0.01Ga0.99N and undoped GaN

Towards an improvement in the spectral description of central stars of planetary nebulae

Context. There are more than 3000 known Galactic planetary nebulae, but only 492 central stars of Galactic planetary nebulae (CSPN) have known spectral types. It is vital to increase this number in order to have reliable statistics, which will lead to an increase of our understanding of these amazing objects. Aims. We aim to contribute to the knowledge of central stars of planetary nebulae and stellar evolution. Methods. This observational study is based on Gemini Multi-Object Spectrographs (GMOS) and with the Intermediate Dispersion Spectrograph (IDS) at the Isaac Newton Telescope spectra of 78 CSPN. The objects were selected because they did not have any previous classification, or the present classification is ambiguous. These new high quality spectra allowed us to identify the key stellar lines for determining spectral classification in the Morgan-Keenan (MK) system. Results. We have acquired optical spectra of a large sample of CSPN. From the observed targets, 50 are classified here for the first time while for 28 the existing classifications have been improved. In seven objects we have identified a P-Cygni profile at the He I lines. Six of these CSPN are late O-Type. The vast majority of the stars in the sample exhibit an absorption-Type spectrum, and in one case we have found wide emission lines typical of [WR] stars. We give a complementary, and preliminary, classification criterion to obtain the sub-Type of the O(H)-Type CSPN. Finally, we give a more realistic value of the proportion of CSPN that are rich or poor in hydrogen.Instituto de Astrofísica de La Plat

Adrenoleucodistrofia ligada al X: presentación de tres casos. Importancia del diagnóstico precoz

X-linked adrenoleukodystrophy is the most common peroxisomal disorder. This disease is caused by a defect in the ABCD1 gen. Saturated very long chain fatty acids are accumulated in serum, adrenal cortex and central nervous system white matter. The clinical spectrum is characterized by progressive neurological dysfunction and adrenal insufficiency with a devastating prognosis. We report a first case of X-linked adrenoleukodystrophy with fatal evolution which identified two asymptomatic family members and established a preventive treatment. Although there is no definitive cure, we stress the importance of family study and evaluation of the individual in situation of risk to establish an early preventive treatment and to give in each particular situation suitable professional advice

Forecasting the success of the WEAVE Wide-Field Cluster Survey on the extraction of the cosmic web filaments around galaxy clusters

Next-generation wide-field spectroscopic surveys will observe the infall regions around large numbers of galaxy clusters with high sampling rates for the first time. Here, we assess the feasibility of extracting the large-scale cosmic web around clusters using forthcoming observations, given realistic observational constraints. We use a sample of 324 hydrodynamic zoom-in simulations of massive galaxy clusters from TheThreeHundred project to create a mock-observational catalogue spanning 5R200 around 160 analogue clusters. These analogues are matched in mass to the 16 clusters targetted by the forthcoming WEAVE Wide-Field Cluster Survey (WWFCS). We consider the effects of the fibre allocation algorithm on our sampling completeness and find that we successfully allocate targets to 81.7 ${\rm {per \,cent}}\, \pm$ 1.3 of the members in the cluster outskirts. We next test the robustness of the filament extraction algorithm by using a metric, Dskel, which quantifies the distance to the filament spine. We find that the median positional offset between reference and recovered filament networks is Dskel = 0.13 ± 0.02 Mpc, much smaller than the typical filament radius of ~ 1 Mpc. Cluster connectivity of the recovered network is not substantially affected. Our findings give confidence that the WWFCS will be able to reliably trace cosmic web filaments in the vicinity around massive clusters, forming the basis of environmental studies into the effects of pre-processing on galaxy evolution

Optical characterisation of InGaN-based microdisk arrays with nanoporous GaN/GaN DBRs

Optically pumped whispering gallery mode (WGM) lasing has been observed in many freestanding microdisk structures. Dry etching is normally used to fabricate the microdisks, which causes severe sidewall damage, resulting in degradation of lasing performance, especially for ultra-small electrically-injected devices. In this paper, we demonstrate high quality microdisk cavities with 3.5 µm diameter, by combining a selective overgrowth approach and an epitaxial lattice-matched distributed Bragg reflector (DBR), topped with a highly reflective (>99%) dielectric DBR. InGaN polaritons are found to occur in the high-quality microcavities. WGM modes are measured, with the positions in good agreement with finite difference time domain simulations. Furthermore, lasing behaviour is observed with a threshold at 410 µW and a dominant mode at 488 nm

Hypogonadotropic hypogonadism in Klinefelter syndrome and hypothalamic-pituitary tumor

El síndrome de Klinefelter es la causa más frecuente de hipogonadismo hipergonadotropo en el varón. La supresión en la respuesta al estímulo con hormona liberadora de la hormona luteinizante en estos pacientes debe hacer sospechar como posible etiología una tumoración a nivel hipotalámico. Se presenta el caso de un paciente diagnosticado a los 4 meses con síndrome de Klinefelter mediante cribado neonatal, con cariotipo 47 XXY, en el que se realizan controles clínicos y analíticos seriados y se encuentran, a los 17 años, valores suprimidos de hormona luteinizante y hormona folículo estimulante. Inicia, posteriormente, cefalea y amaurosis de ojo izquierdo, y se encuentra, en una resonancia magnética cerebral, un tumor germinal mixto a nivel hipotalámico, que precisa tratamiento quirúrgico, quimioterapia y radioterapia, con respuesta favorable. Klinefelter Syndrome is the most frequent cause of hypergonadotropic hypogonadism in men. A flat response at luteinizing hormone releasing hormone stimulation test could be the first sign of hypothalamic tumor in these patients. We report the case of a patient diagnosed by neonatal screening with Klinefelter Syndrome, 47 XXY, that at 17 years follow-up presents analytical modification of the response to luteinizing hormone releasing hormone stimulation test with suppressed luteinizing hormone and follicle-stimulating hormone values; lately he presents with headache and loss of left eye vision. A magnetic resonance imaging of the brain showed a mixed germ cell hypothalamus tumor, requiring surgery, chemotherapy and radiotherapy with optimal response