Batrachospermum Roth. (Rhodophyta), a genus of red algae new to Iowa

Batrachospermum, a floridean red alga, is formally reported from Iowa. Populations have been observed by several workers at nine localities in eight counties: Black Hawk, Bremer, Des Moines, Dickinson, Dubuque, Emmet, Hancock, and Webster. The habitats include permanent and intermittent streams, a distrophic lake, and prairie marshes. To date, the species include B. ectocarpum Sir. from a stream in Webster County , and an undescribed species from a prairie marsh in Black Hawk County. A discussion of the taxonomy and occurrence of Batrachospermum in Iowa in presented. With this report, four genera of freshwater red algae are known from Iowa

OPPORTUNITY COSTS OF WATER LEASING: IRRIGATION, INSTREAM FLOW, AND WETLAND CONSIDERATIONS IN THE LARAMIE BASIN, WYOMING

Flood irrigation in the Laramie Basin of southeast Wyoming has created many wetlands that rely directly on irrigation inputs for water. The Laramie Basin is a proposed water source for enhancing Platte River instream flows, to the benefit of endangered cranes, terns, plovers, and sturgeons. Increasing irrigation efficiency, or retiring irrigated lands would transform Laramie Basin agriculture and cause a high fraction of the Basins wetlands to be lost. This study explores the limitations of traditional water transfer tools when regional instream-flow requirements compete for water with local irrigation-dependent wetlands. A rotating short-term water lease program is proposed. The program would allow Laramie Basin producers to contribute to instream flow without causing permanent wetland damage or loss. Short-term water leasing programs could allow agricultural communities to contribute to regional environmental water needs without sacrificing local, agriculturally-based ecological resources. An estimate of minimum water costs, advantages and disadvantages of short-term water leasing are discussed.Resource /Energy Economics and Policy,

Analysis of ontogenetic growth trends in two marine Antarctic bivalves Yoldia eightsi and Laternula elliptica: Implications for sclerochronology

There is an increasing use of marine species as paleoclimate recorders for the marine realm. These archives provide novel baseline records of past oceanographic variability in regions devoid of instrumental observations. Here we report results of a study of the ontogenetic growth pattern of two Antarctic marine bivalve molluscs: Yoldia eightsi and Laternula elliptica from West Antarctic Peninsula populations using negative exponential detrending technique and multi-taper method spectral analysis. Our data show the growth of both Y. eightsi and L. elliptica follow a general negative exponential trend over their longevity. However, our analyses also identified an innate 9.06 year periodic endogenous growth rhythm in the growth increment pattern of Y. eightsi and two innate periodic growth rhythms, 5 and 6.6 year period, were found in L. elliptica. We hypothesize that the Y. eightsi endogenous growth rhythm may be related to the reallocation of energetic resources between somatic growth and gametogenesis although more biological data are required to test this hypothesis. Further work into L. elliptica biology is required to understand the possible meaning of the innate growth rhythms found for this species. The identification growth rhythms is important not only for their biological significance but also in sclerochronological analysis because of their importance in developing paleoenvironmental reconstructions

Centerscope

Centerscope, formerly Scope, was published by the Boston University Medical Center "to communicate the concern of the Medical Center for the development and maintenance of improved health care in contemporary society.

Coactivation index of children with congenital upper limb reduction deficiencies before and after using a wristdriven 3D printed partial hand prosthesis

Background: Co-contraction is the simultaneous activation of agonist and antagonist muscles that produces forces around a joint. It is unknown if the use of a wrist-driven 3D printed transitional prostheses has any influence on the neuromuscular motor control strategies of the affected hand of children with unilateral upper-limb reduction deficiencies. Thus, the purpose of the current investigation was to examine the coactivation index (CI) of children with congenital upper-limb reduction deficiencies before and after 6 months of using a wrist-driven 3D printed partial hand prosthesis. Methods: Electromyographic activity of wrist flexors and extensors (flexor carpi ulnaris and extensor digitorum) was recorded during maximal voluntary contraction of the affected and non-affected wrists. Co-contraction was calculated using the coactivation index and was expressed as percent activation of antagonist over agonist. Nine children (two girls and seven boys, 6 to 16 years of age) with congenital upper-limb deficiencies participated in this study and were fitted with a wrist-driven 3D printed prosthetic hand. From the nine children, five (two girls and three boys, 7 to 10 years of age) completed a second visit after using the wrist-driven 3D printed partial hand prosthesis for 6 months. Results: Separate two-way repeated measures ANOVAs were performed to analyze the coactivation index and strength data. There was a significant main effect for hand with the affected hand resulting in a higher coactivation index for flexion and extension than the non-affected hand. For wrist flexion there was a significant main effect for time indicating that the affected and non-affected hand had a significantly lower coactivation index after a period of 6 months. Conclusion: The use of a wrist-driven 3D printed hand prosthesis lowered the coactivation index by 70% in children with congenital upper limb reduction deficiencies. This reduction in coactivation and possible improvement in motor control strategies can potentially improve prosthetic rehabilitation outcomes

Metatranscriptomic Sequencing of Winter and Spring Planktonic Communities from Lake Erie, a Laurentian Great Lake

Previous reports suggest planktonic and under-ice winter microbial communities in Lake Erie are dominated by diatoms. Here, we report the assembled metatranscriptomes of 79 Lake Erie surface water microbial communities spanning both the winter (28 samples) and spring (51 samples) months over spatial, temporal, and climatic gradients in 2019 through 2020

South Georgia marine productivity over the past 15 ka and implications for glacial evolution

The subantarctic islands of South Georgia are located in the Southern Ocean, and they may be sensitive to future climate warming. However, due to a lack of well-dated subantarctic palaeoclimate archives, there is still uncertainty about South Georgia’s response to past climate change. Here, we reconstruct primary productivity changes and infer Holocene glacial evolution by analysing two marine gravity cores: one near Cumberland Bay on the inner South Georgia shelf (GC673: ca. 9.5 to 0.3cal.kyrBP) and one offshore of Royal Bay on the mid-shelf (GC666: ca. 15.2cal.kyrBP to present). We identify three distinct benthic foraminiferal assemblages characterised by the dominance of Miliammina earlandi, Fursenkoina fusiformis, and Cassidulinoides parkerianus that are considered alongside foraminiferal stable isotopes and the organic carbon and biogenic silica accumulation rates of the host sediment. The M. earlandi assemblage is prevalent during intervals of dissolution in GC666 and reduced productivity in GC673. The F. fusiformis assemblage coincides with enhanced productivity in both cores. Our multiproxy analysis provides evidence that the latest Pleistocene to earliest Holocene (ca. 15.2 to 10.5cal.kyrBP) was a period of high productivity associated with increased glacial meltwater discharge. The mid–late Holocene (ca. 8 to 1cal.kyrBP), coinciding with a fall in sedimentation rates and lower productivity, was likely a period of reduced glacial extent but with several short-lived episodes of increased productivity from minor glacial readvances. The latest Holocene (from ca. 1cal.kyrBP) saw an increase in productivity and glacial advance associated with cooling temperatures and increased precipitation which may have been influenced by changes in the southwesterly winds over South Georgia. We interpret the elevated relative abundance of F. fusiformis as a proxy for increased primary productivity which, at proximal site GC673, was forced by terrestrial runoff associated with the spring–summer melting of glaciers in Cumberland Bay. Our study refines the glacial history of South Georgia and provides a more complete record of mid–late Holocene glacial readvances with robust chronology. Our results suggest that South Georgia glaciers were sensitive to modest climate changes within the Holocene

Survey of highly non-Keplerian orbits with low-thrust propulsion

Celestial mechanics has traditionally been concerned with orbital motion under the action of a conservative gravitational potential. In particular, the inverse square gravitational force due to the potential of a uniform, spherical mass leads to a family of conic section orbits, as determined by Isaac Newton, who showed that Kepler‟s laws were derivable from his theory of gravitation. While orbital motion under the action of a conservative gravitational potential leads to an array of problems with often complex and interesting solutions, the addition of non-conservative forces offers new avenues of investigation. In particular, non-conservative forces lead to a rich diversity of problems associated with the existence, stability and control of families of highly non-Keplerian orbits generated by a gravitational potential and a non-conservative force. Highly non-Keplerian orbits can potentially have a broad range of practical applications across a number of different disciplines. This review aims to summarize the combined wealth of literature concerned with the dynamics, stability and control of highly non-Keplerian orbits for various low thrust propulsion devices, and to demonstrate some of these potential applications

Recombinant ADAMTS13 reduces abnormally up-regulated von Willebrand factor in plasma from patients with severe COVID-19

Thrombosis affecting the pulmonary and systemic vasculature is common during severe COVID-19 and causes adverse outcomes. Although thrombosis likely results from inflammatory activation of vascular cells, the mediators of thrombosis remain unconfirmed. In a cross-sectional cohort of 36 severe COVID-19 patients, we show that markedly increased plasma von Willebrand factor (VWF) levels were accompanied by a partial reduction in the VWF regulatory protease ADAMTS13. In all patients we find this VWF/ADAMTS13 imbalance to be associated with persistence of ultra-high-molecular-weight (UHMW) VWF multimers that are highly thrombogenic in some disease settings. Incubation of plasma samples from patients with severe COVID-19 with recombinant ADAMTS13 (rADAMTS13) substantially reduced the abnormally high VWF activity, reduced overall multimer size and depleted UHMW VWF multimers in a time and concentration dependent manner. Our data implicate disruption of normal VWF/ADAMTS13 homeostasis in the pathogenesis of severe COVID-19 and indicate that this can be reversed ex vivo by correction of low plasma ADAMTS13 levels. These findings suggest a potential therapeutic role for rADAMTS13 in helping restore haemostatic balance in COVID-19 patients