Physical and psychological health of medical students involved in the coronavirus disease 2019 response in Switzerland.

Students involved in the COVID-19 response reported a similar proportion of COVID-19 symptoms or confirmed diagnoses, but lower levels of anxiety, depression and burnout compared with their non-involved peers

GDNF reduces drug-induced rotational behavior after medial forebrain bundle transection by a mechanism not involving striatal dopamine

Parkinson's disease (PD) is characterized by the progressive loss of the substantia nigra (SN) dopaminergic neurons projecting to the striatum. Neurotrophic factors may have the potential to prevent or slow down the degenerative process occurring in PD. To that end, we examined whether low amounts of glial cell line-derived neurotrophic factor (GDNF) continuously released from polymer-encapsulated genetically engineered cells are able to prevent the loss of tyrosine hydroxylase immunoreactivity (TH-IR) in SN neurons and ameliorate the amphetamine-induced rotational asymmetry in rats that have been subjected to a unilateral medial forebrain bundle (MFB) axotomy. Baby hamster kidney (BHK) cells transfected with the cDNA for GDNF were encapsulated in a polymer fiber and implanted unilaterally at a location lateral to the MFB and rostral to the SN. ELISA assays before implantation show that the capsules release approximately 5 ng of GDNF/capsule per day. One week later, the MFB was axotomized unilaterally ipsilateral to the capsule placement. Seven days later, the animals were tested for amphetamine-induced rotational asymmetry and killed. The striatum was excised and analyzed either for catecholamine content or TH-IR, while the SN was immunostained for the presence of TH-IR. GDNF did not prevent the loss of dopamine in the striatum. However, GDNF significantly rescued TH-IR neurons in the SN pars compacta. Furthermore, GDNF also significantly reduced the number of turns per minute ipsilateral to the lesion under the influence of amphetamine. Improvement of rotational behavior in the absence of dopaminergic striatal reinnervation may reflect neuronal plasticity in the SN, as suggested by the dendritic sprouting observed in animals receiving GDNF. These results illustrate that the continuous release of low levels of GDNF close to the SN is capable of protecting the nigral dopaminergic neurons from an axotomy-induced lesion and significantly improving pharmacological rotational behavior by a mechanism other than dopaminergic striatal reinnervation

Lentiviral-mediated delivery of mutant huntingtin in the striatum of rats induces a selective neuropathology modulated by polyglutamine repeat size, huntingtin expression levels, and protein length.

A new strategy based on lentiviral-mediated delivery of mutant huntingtin (htt) was used to create a genetic model of Huntington's disease (HD) in rats and to assess the relative contribution of polyglutamine (CAG) repeat size, htt expression levels, and protein length on the onset and specificity of the pathology. Lentiviral vectors coding for the first 171, 853, and 1520 amino acids of wild-type (19 CAG) or mutant htt (44, 66, and 82 CAG) driven by either the phosphoglycerate kinase 1 (PGK) or the cytomegalovirus (CMV) promoters were injected in rat striatum. A progressive pathology characterized by sequential appearance of ubiquitinated htt aggregates, loss of dopamine- and cAMP-regulated phosphoprotein of 32 kDa staining, and cell death was observed over 6 months with mutant htt. Earlier onset and more severe pathology occurred with shorter fragments, longer CAG repeats, and higher expression levels. Interestingly, the aggregates were predominantly located in the nucleus of PGK-htt171-injected rats, whereas they were present in both the nucleus and processes of CMV-htt171-injected animals expressing lower transgene levels. Finally, a selective sparing of interneurons was observed in animals injected with vectors expressing mutant htt. These data demonstrate that lentiviral-mediated expression of mutant htt provides a robust in vivo genetic model for selective neural degeneration that will facilitate future studies on the pathogenesis of cell death and experimental therapeutics for HD

Intentionality and Agency in Security

Weiser [13] said that the best software is that which just blends in and disap- pears. Security software has been at odds with this principle as it attempts to attract user attention whenever possible—it has been largely designed to be visible to the user and ask them to take action. For example, anti-virus software proudly notifies the user how many viruses it has stopped while websites dis- play padlocks and security seals. Users are disrupted in their work by security notifications, asked to read warnings and decide whether they want to heed or ignore them.ERC 30722

Cooper pair delocalization in disordered media

We discuss the effect of disorder on the coherent propagation of the bound state of two attracting particles. It is shown that a result analogous to the Anderson theorem for dirty superconductors is also valid for the Cooper problem, namely, that the pair wave function is extended beyond the single-particle localization length if the latter is large. A physical justification is given in terms of the Thouless block-scaling picture of localization. These arguments are supplemented by numerical simulations. With increasing disorder we find a transition from a regime in which the interaction delocalizes the pair to a regime in which the interaction enhances localization.Comment: 5 pages, RevTex with 2 figures include

The risk of extinction for birds in Great Britain

t Over the last 20 years,species priorities for bird conservation in the UK have been guided by ‘Birds of Conservation Concern’ – an in-depth assessment made possible by the top-class data available on the status of the UK’s birds. For other wildlife, priorities tend to be informed by measures of extinction risk, generated by the IUCN Regional Red List process.We carried out the first formal IUCN assessment for birds in Great Britain. Of the 241 species assessed, 100 (43%) had at least one population (breeding and/or non-breeding) that qualified as Threatened using the standard IUCN Red List criteria and categories. Of 289 separate assessments of breeding or non-breeding populations, 39% qualified as Threatened (8% Critically Endangered, 14% Endangered, 17% Vulnerable) with a further 10% classified as Near Threatened. Both Golden Oriole Oriolus oriolus and Fieldfare Turdus pilaris were assessed as being Critically Endangered (Possibly Extinct) as breeding species, in addition to seven species that are already extinct (either Extinct or Regionally Extinct). The proportion of GB birds qualifying as Threatened was high compared with birds elsewhere in Europe and other taxonomic groups in GB. We believe that, if similar data were available, levels of extinction risk would be higher for other areas/taxa than is currently estimated

Effectiveness and safety of the angiotensin II antagonist irbesartan in children with chronic kidney diseases

Background: Studies in adults with chronic kidney diseases demonstrate that the orally available angiotensin II antagonist irbesartan reduces arterial pressure and pathological proteinuria, mostly with an excellent tolerability profile. Little information is available on irbesartan in childhood. Methods: A total of 44 pediatric outpatients with chronic kidney disease (27 male and 17, aged 3.7 to 18 years, median 10 years) were given irbesartan once a day during 18 weeks for arterial hypertension (N = 23), proteinuria (N = 8), or both (N = 13). Results: In patients with hypertension, the use of irbesartan 4.1 (3.1-5.3) mg/kg body weight daily (median and interquartile range) was associated with a decrease (P < .005) in arterial pressure by 17 (13-22)/10 (7-12) mm Hg. In patients with overt proteinuria the urinary protein excretion decreased (P < .01) during treatment with irbesartan (2.9 [2.0-4.8] mg/kg body weight) by 52 (0-75) mg/[m2 × h]), whereas plasma albumin increased (P < .05) by 4 (1-5) g/L. The frequency of abdominal pain, constipation, cough, diarrhea, dizziness, edema, fatigue, headache, insomnia, myalgia, orthostasis, and rash was similar before and with irbesartan. Plasma sodium slightly decreased, whereas plasma potassium increased, with irbesartan (P < .01). Conclusions: In pediatric patients with chronic kidney diseases, irbesartan given once a day for 18 weeks significantly reduces arterial pressure and proteinuria, with an excellent tolerability and side effect profile. Am J Hypertens 2002;15:1057-1063 © 2002 American Journal of Hypertension, Lt

Charge and spin order in one-dimensional electron systems with long-range Coulomb interactions

We study a system of electrons interacting through long--range Coulomb forces on a one--dimensional lattice, by means of a variational ansatz which is the strong--coupling counterpart of the Gutzwiller wave function. Our aim is to describe the quantum analogue of Hubbard's classical ``generalized Wigner crystal''. We first analyse charge ordering in a system of spinless fermions, with particular attention to the effects of lattice commensurability. We argue that for a general (rational) number of electrons per site $n$ there are three regimes, depending on the relative strength $V$ of the long--range Coulomb interaction (as compared to the hopping amplitude $t$). For very large $V$ the quantum ground state differs little from Hubbard's classical solution, for intermediate to large values of $V$ we recover essentially the Wigner crystal of the continuum model, and for small $V$ the charge modulation amounts to a small--amplitude charge--density wave. We then include the spin degrees of freedom and show that in the Wigner crystal regimes (i.e. for large $V$) they are coupled by an antiferromagnetic kinetic exchange $J$, which turns out to be smaller than the energy scale governing the charge degrees of freedom. Our results shed new light on the insulating phases of organic quasi--1D compounds where the long--range part of the interaction is unscreened, and magnetic and charge orderings coexist at low temperatures.Comment: 11 pages, 7 figures, accepted for publication on Phys. Rev.

Dielectric catastrophe at the Mott transition

We study the Mott transition as a function of interaction strength in the half-filled Hubbard chain with next-nearest-neighbor hopping t' by calculating the response to an external electric field using the Density Matrix Renormalization Group. The electric susceptibility chi diverges when approaching the critical point from the insulating side. We show that the correlation length xi characterizing this transition is directly proportional to fluctuations of the polarization and that chi ~ xi^2. The critical behavior shows that the transition is infinite-order for all t', whether or not a spin gap is present, and that hyperscaling holds.Comment: 4 pages, 4 eps figures, REVTe