Photosynthetic responses in the inducible mechanisms of desiccation tolerance of a liverwort and a moss

Chlorophyll fluorescence was used to study the effect of hardening treatments on aspects of desiccation tolerance in the liverwort Dumortiera hirsuta and the moss Atrichum androgynum. After desiccation the recovery of PS2 was monitored during rehydration. We show that partial dehydration and ABA treatments can increase desiccation tolerance. In A. androgynum, the increased desiccation tolerance is accompanied by increased NPQ. However, hardening decreases the efficiency of photosynthesis in unstressed plants as well. In D. hirsuta, as for Atrichum, treatment with ABA greatly increased desiccation tolerance. D. hirsuta was much more responsive to ABA hardening than Atrichum. Unlike Atrichum, increased desiccation tolerance was not accompanied by increased NPQ and decreased PS2 efficiency. While partial dehydration hardening had little effect on the liverwort before stress, hardened plants displayed a moderate (22%) but significant improvement in PS2 activity 1 h following rehydration. As for the ABA hardening treatments, improved recovery of PS2 activity was not accompanied by increased NPQ, and NPQ was actually lower in hardened plants. Partial dehydration can increase tolerance in D. hirsuta, however, the increases were less than those induced by ABA. The mechanism of the hardening-induced increases in desiccation tolerance appear quite different in the two species

Observations of Shadow Bands at the Total Solar Eclipse of 16 February 1980

Photoelectric observations of short term light variations (shadow bands) at the 16 Feb. 1980 total solar eclipse have been made using a set of spatially separated PIN diodes. Light variations in a bandpass of 1-500 Hz were detected during the half-minutes preceding and following the total phase. Fourier analysis of the noise spectrum of the variations reveals a sharp drop-off for frequencies about 50 Hz and an overall spectrum quite similar to previously reported power spectra of stellar scintillation. This is consistent with an atmospheric origin for the shadow bands. Cross-correlations between the detector outputs are low, suggesting a short persistence time for the turbulent elements causing the patterns

A Desktop Universe for the Introductory Astronomy Laboratory

What is a well-intentioned astronomy instructor to do? There is no argument that experience with the real world is desirable in any astronomy course, especially the introductory classes that fulfill the science distribution requirements at many colleges and universities. Though it is a simple matter to take students out of doors, show them the motions of the Sun, Moon, and stars, and have them squint for a few seconds at Saturn\u27s rings through a telescope, these activities represent only a small portion of the subject matter of modern astronomy. It is simply not possible, given the constraints of time, weather, and equipment at most schools, to have students determine the photometric distance of a star cluster, measure the dispersion distance of a pulsar, or confirm Hubble\u27s redshift-distance relation for themselves. [excerpt

Studie zur psychischen Gesundheit von Schülerinnen und Schülern im Freistaat Sachsen im Zusammenhang mit der Corona-Pandemie

Ziel der Studie ist es, einen Überblick über die Entwicklung der psychischen Gesundheit von Schülern der 5. bis 10. Klassen (Sekundarstufe I) im Freistaat Sachsen in den vergangenen Jahren zu bekommen. Dabei sollen vor allem der zeitliche Verlauf vor und seit Beginn der Corona-Pandemie im März 2020 und damit einhergehende Schutzmaßnahmen im Mittelpunkt stehen. Basierend auf den Ergebnissen der Studie sollen Aussagen getroffen werden, inwiefern und in welchem Ausmaß die Pandemie Einfluss auf die psychische Gesundheit von Kindern und Jugendlichen genommen hat. Sie dienen als Grundlage für das weitere Handeln des Freistaats Sachsen und die Sicherung der kinder- und jugendpsychiatrischen sowie -psychotherapeutischen Versorgung. Redaktionsschluss: 31.01.202

Electoral Dioramas: On the Problem of Representation in Voting Advice Applications

Voting Advice Applications (VAAs) are online tools designed to help citizens decide how to vote. They typically offer their users a representation of what is at stake in an election by matching user preferences on issues with those of parties or candidates. While the use of VAAs has boomed in recent years in both established and new democracies, this new phenomenon in the electoral landscape has received little attention from political theorists. The current academic debate is focused on epistemic aspects of the question how a VAA can adequately represent electoral politics. We argue that conceptual and normative presuppositions at play in the background of the tool are at least as important. Even a well-developed VAA does not simply reflect what is at stake in the election by neutrally passing along information. Rather, it structures political information in a way that is informed by the developers’ presuppositions. Yet, these presuppositions remain hidden if we interpret the tool as a mirror that offers the user a reflection of him/herself situated within the political landscape. VAAs should therefore be understood as electoral dioramas, staged according to a contestable picture of politics

UBVRI Photometry of the Type Ia SN 1994D in NGC 4526

We present optical photometry for the type Ia SN 1994D in NGC 4526 from 1994 March 7 to June 4 starting 13 days before B-band maximum. The light curves of this SN resemble closely those of the normal type Ia events SNe 1989B and 1980N, differing only in a slightly faster decline after maximum in VRI. The optical absolute magnitudes of SN 1994D, however, are significantly brighter than those of its near twins, and brighter than those predicted by Phillips\u27 [ApJ, 413, L105 (1993)] relationship between decline rate and luminosity. Our small amount of IR photometry of SN 1994D is not inconsistent with that of other type IA SNe

Incorporating metapopulation Dynamics to Inform Invasive Species Management: Evaluating Bighead and Silver Carp Control Strategies in the Illinois River

1. Invasive species management can benefit from predictive models that incorporate spatially explicit demographics and dispersal to guide resource allocation decisions. 2. We used invasive bigheaded carps (Hypophthalmichthys spp.) in the Illinois River, USA as a case study to create a spatially explicit model to evaluate the allocation of future management efforts. Specifically, we compared additional harvest (e.g. near the invasion front vs. source populations) and enhanced movement deterrents to meet the management goal of reducing abundance at the invasion front. 3. We found additional harvest in lower river pools (i.e. targeting source populations) more effectively limited population sizes upriver at the invasion front compared to allocating the same harvest levels near the invasion front. Likewise, decreasing passage (i.e. lock and dam structures) at the farthest, feasible downriver location limited invasion front population size more than placing movement deterrents farther upriver. 4. Synthesis and applications. Our work highlights the benefits of adopting a multipronged approach for invasive species management, combining suppression of source populations with disrupting movement between source and sink populations thereby producing compounding benefits for control. Our results also demonstrate the importance of considering metapopulation dynamics for invasive species control programs when achieving long-term management goals

Adverse Cerebral Outcomes after Coronary Bypass Surgery

ABSTRACT Background Acute changes in cerebral function after elective coronary bypass surgery are a difficult clinical problem. We carried out a multicenter study to determine the incidence and predictors of — and the use of resources associated with — perioperative adverse neurologic events, including cerebral injury. Methods In a prospective study, we evaluated 2108 patients from 24 U.S. institutions for two general categories of neurologic outcome: type I (focal injury, or stupor or coma at discharge) and type II (deterioration in intellectual function, memory deficit, or seizures). Results Adverse cerebral outcomes occurred in 129 patients (6.1 percent). A total of 3.1 percent had type I neurologic outcomes (8 died of cerebral injury, 55 had nonfatal strokes, 2 had transient ischemic attacks, and 1 had stupor), and 3.0 percent had type II outcomes (55 had deterioration of intellectual function and 8 had seizures). Patients with adverse cerebral outcomes had higher in-hospital mortality (21 percent of patients with type I outcomes died, vs. 10 percent of those with type II and 2 percent of those with no adverse cerebral outcome; P0.001 for all comparisons), longer hospitalization (25 days with type I outcomes, 21 days with type II, and 10 days with no adverse outcome; P0.001), and a higher rate of discharge to facilities for intermediate- or long-term care (47 percent, 30 percent, and 8 percent; P0.001). Predictors of type I outcomes were proximal aortic atherosclerosis, a history of neurologic disease, and older age; predictors of type II outcomes were older age, systolic hypertension on admission, pulmonary disease, and excessive consumption of alcohol. Conclusions Adverse cerebral outcomes after coronary bypass surgery are relatively common and serious; they are associated with substantial increases in mortality, length of hospitalization, and use of intermediate- or long-term care facilities. New diagnostic and therapeutic strategies must be developed to lessen such injury. (N Engl J Med 1996;335:1857-63.)

The Role of Particulate Matter-Associated Zinc in Cardiac Injury in Rats

Background: Exposure to particulate matter (PM) has been associated with increased cardiovascular morbidity; however, causative components are unknown. Zinc is a major element detected at high levels in urban air.Objective We investigated the role of PM-associated zinc in cardiac injury. Methods: We repeatedly exposed 12- to 14-week-old male Wistar Kyoto rats intratracheally (1×/week for 8 or16 weeks) to a) saline (control); b) PM having no soluble zinc (Mount St. Helens ash, MSH); or c) whole-combustion PM suspension containing 14.5 μg/mg of water-soluble zinc at high dose (PM-HD) and d ) low dose (PM-LD), e) the aqueous fraction of this suspension (14.5 μg/mg of soluble zinc) (PM-L), or f ) zinc sulfate (rats exposed for 8 weeks received double the concentration of all PM components of rats exposed for 16 weeks). Results: Pulmonary inflammation was apparent in all exposure groups when compared with saline (8 weeks greater than 16 weeks). PM with or without zinc, or with zinc alone caused small increases in focal subepicardial inflammation, degeneration, and fibrosis. Lesions were not detected in controls at 8 weeks but were noted at 16 weeks. We analyzed mitochondrial DNA damage using quantitative polymerase chain reaction and found that all groups except MSH caused varying degrees of damage relative to control. Total cardiac aconitase activity was inhibited in rats receiving soluble zinc. Expression array analysis of heart tissue revealed modest changes in mRNA for genes involved in signaling, ion channels function, oxidative stress, mitochondrial fatty acid metabolism, and cell cycle regulation in zinc but not in MSH-exposed rats. Conclusion: These results suggest that water-soluble PM-associated zinc may be one of the causal components involved in PM cardiac effects

Mouse large-scale phenotyping initiatives: overview of the European Mouse Disease Clinic (EUMODIC) and of the Wellcome Trust Sanger Institute Mouse Genetics Project.

Two large-scale phenotyping efforts, the European Mouse Disease Clinic (EUMODIC) and the Wellcome Trust Sanger Institute Mouse Genetics Project (SANGER-MGP), started during the late 2000s with the aim to deliver a comprehensive assessment of phenotypes or to screen for robust indicators of diseases in mouse mutants. They both took advantage of available mouse mutant lines but predominantly of the embryonic stem (ES) cells resources derived from the European Conditional Mouse Mutagenesis programme (EUCOMM) and the Knockout Mouse Project (KOMP) to produce and study 799 mouse models that were systematically analysed with a comprehensive set of physiological and behavioural paradigms. They captured more than 400 variables and an additional panel of metadata describing the conditions of the tests. All the data are now available through EuroPhenome database (www.europhenome.org) and the WTSI mouse portal (http://www.sanger.ac.uk/mouseportal/), and the corresponding mouse lines are available through the European Mouse Mutant Archive (EMMA), the International Knockout Mouse Consortium (IKMC), or the Knockout Mouse Project (KOMP) Repository. Overall conclusions from both studies converged, with at least one phenotype scored in at least 80% of the mutant lines. In addition, 57% of the lines were viable, 13% subviable, 30% embryonic lethal, and 7% displayed fertility impairments. These efforts provide an important underpinning for a future global programme that will undertake the complete functional annotation of the mammalian genome in the mouse model