Chronic thoracic hemisection spinal cord injury in adult rats induces a progressive decline in transmission from uninjured fibers to lumbar motoneurons

Although most spinal cord injuries are anatomically incomplete, only limited functional recovery has been observed in people and rats with partial lesions. To address why surviving fibers cannot mediate more complete recovery, we evaluated the physiological and anatomical status of spared fibers after unilateral hemisection (HX) of thoracic spinal cord in adult rats. We made intracellular and extracellular recordings at L5 (below HX) in response to electrical stimulation of contralateral white matter above (T6) and below (L1) HX. Responses from T6 displayed reduced amplitude, increased latency and elevated stimulus threshold in the fibers across from HX, beginning 1-2 weeks after HX. Ultrastructural analysis revealed demyelination of intact axons contralateral to the HX, with a time course similar to the conduction changes. Behavioral studies indicated partial recovery which arrested when conduction deficits began. These findings suggest a chronic pathological state in intact fibers and necessity for prompt treatment to minimize it

A Statistical Estimator for Determining the Limits of Contemporary and Historic Phenology

Climate change affects not just where species are found, but also when species’ key life-history events occur—their phenology. Measuring such changes in timing is often hampered by a reliance on biased survey data: surveys identify that an event has taken place (for example, the flower is in bloom), but not when that event happened (for example, the flower bloomed yesterday). Here, we show that this problem can be circumvented using statistical estimators, which can provide accurate and unbiased estimates from sparsely sampled observations. We demonstrate that such methods can resolve an ongoing debate about the relative timings of the onset and cessation of flowering, and allow us to place modern observations reliably within the context of the vast wealth of historical data that reside in herbaria, museum collections, and written records. We also analyse large-scale citizen science data from the United States National Phenology Network and reveal not just earlier but also potentially more variable flowering in recent years. Evidence for greater variability through time is important because increases in variation are characteristic of systems approaching a state change

Plasma plume effects on the conductivity of amorphous-LaAlO₃/SrTiO₃ interfaces grown by pulsed laser deposition in O₂ and Ar

Amorphous LaAlO3/SrTiO3 interfaces exhibit metallic conductivity similarto those found for the extensively studied crystalline-LaAlO3/SrTiO3 interfaces. Here, we investigate the conductivity of the amorphous-LaAlO3/SrTiO3 interfaces grown in different pressures of O2 and Ar background gases. During the deposition, the LaAlO3 ablation plume is also studied, in situ, by fast photography and space-resolved optical emission spectroscopy. An interesting correlation between interfacial conductivity and kinetic energy of the Al atoms in the plume is observed: to assure conducting interfaces of amorphous-LaAlO3/SrTiO3, the kinetic energy of Al should be higher than 1 eV. Our findings add further insights on mechanisms leading to interfacial conductivity in SrTiO3-based oxide heterostructures

Control of termites and other soil pests of groundnuts with special reference to controlled release formulations of non-persistent insecticides in India and Sudan

Trials for the control of soil pests, particularly of termites (Isoptera:Termitidae), in groundnuts (Arachis hypogaea) in India and Sudan used chlorpyrifos and isofenphos granules, chlorpyrifos, phorate, carbosulfan and carbofuran in controlled release formulations, and chlorpyrifos seed dressing. Their effects on foliar pests were also noted. Chlorpyrifos controlled release pellets were as effective as aldrin, used as a standard, in reducing root and pod attack and, like aldrin, doubled yields. Isofenphos and chlorpyrifos granules increased yields and reduced pod damage, but to a lesser extent. Other treatments were less effective. Carbosulfan and phorate controlled release and isofenphos granules reduced leaf miner attack. These trials establish the efficacy of controlling termites and other soil pests with controlled release formulations of otherwise non-persistent insecticides. However, the expensive formulation is unlikely to be cost-effective for rural farmers in developing countries and, in the case of chlorpyrifos , residue levels in kernels may be unacceptable. Future work should investigate other insecticides in the formulation and development of cheaper controlled release matrice

Reply to: “Global Conservation of Phylogenetic Diversity Captures More Than Just Functional Diversity”

Academic biologists have long advocated for conserving phylogenetic diversity (PD), often (but not exclusively) on the basis that PD is a useful proxy for “feature diversity”, defined as the variety of forms and functions represented in set of organisms (see below for an extended discussion of this definition). In a recent paper, we assess the extent to which this proxy (which we coined the “phylogenetic gambit”) holds in three empirical datasets (terrestrial mammals, birds, and tropical marine fishes) when using functional traits and functional diversity (FD) to operationalize feature diversity. Owen et al. offer a criticism of our methods for quantifying feature diversity with FD and disagree with our conclusions. We are grateful that Owen et al. have engaged thoughtfully with our work, but we believe there are more points of agreement than Owen et al. imply

Asymmetric patterns of recovery in two habitat forming seagrass species following simulated overgrazing by urchins

The persistence of seagrass meadows reflects variation in factors that influence their productivity and consumption. Sea urchins (Amblypneustes pallidus) can over-graze seagrass (Amphibolis antarctica) to create sparse meadows in South Australia, but this effect is not observed in adjacent Posidonia sinuosa meadows despite greater densities of inhabiting urchins. To test the effect of urchin grazing on seagrass biomass, we elevated the density of urchins in meadows of A. antarctica and P. sinuosa and quantified seagrass decline. Urchins removed similar amounts of biomass from both seagrass species, but the loss of leaf meristems was 11-times greater in A. antarctica than in P. sinuosa. In a second experiment to assess the recovery of seagrass, we simulated urchin grazing by clipping seagrass to mimic impacts measured in the first experiment, as well as completely removing all above ground biomass in one treatment. Following simulated grazing, P. sinuosa showed a rapid trajectory toward recovery, while A. antarctica meadows continued to decline relative to control treatments. While both A. antarctica and P. sinuosa were susceptible to heavy grazing loss, consumption of the exposed meristems of A. antarctica appears to reduce its capacity to recover, which may increase its vulnerability to long-term habitat phase-shifts and associated cascading ecosystem changes. © 2013 Elsevier B.V.Owen W. Burnell, Sean D. Connell, Andrew D. Irving, Bayden D. Russel

Prioritizing Phylogenetic Diversity Captures Functional Diversity Unreliably

In the face of the biodiversity crisis, it is argued that we should prioritize species in order to capture high functional diversity (FD). Because species traits often reflect shared evolutionary history, many researchers have assumed that maximizing phylogenetic diversity (PD) should indirectly capture FD, a hypothesis that we name the “phylogenetic gambit”. Here, we empirically test this gambit using data on ecologically relevant traits from \u3e15,000 vertebrate species. Specifically, we estimate a measure of surrogacy of PD for FD. We find that maximizing PD results in an average gain of 18% of FD relative to random choice. However, this average gain obscures the fact that in over one-third of the comparisons, maximum PD sets contain less FD than randomly chosen sets of species. These results suggest that, while maximizing PD protection can help to protect FD, it represents a risky conservation strategy

The Use of Antisense-Mediated Inhibition to Delineate The Role of Inflammatory Agents in The Pathophysiology of Spinal Cord Injury

Injuries to the central nervous system (CNS) usually lead to a potent and acute inflammatory response[1]. During this period, glia and immune cells respond to chemical cues associated with the debris of lysed neurons, disrupted axons, and a broken blood-brain-barrier by releasing a battery of cytokines including tumor necrosis factor-α (TNF-α) and, interleukin-β (IL-1β) as well as reactive oxygen species such as nitric oxide (NO-)[2]. The secretion of these factors may be primarily responsible for secondary damage to surrounding uninjured tissue that potentiates the initial injury[3]. Antisense oligonucleotides (ASOs) are designed to hybridize to specific regions of specific mRNAs. Hybridization of the oligonucleotide to the mRNA then interferes with the normal processing of that mRNA at the ribosome or targets the RNA duplex for cleavage by the RNA digestive enzyme, ribonuclease H, resulting in greatly reduced expression of the coded protein. This effectively reduces the amount of corresponding translated protein product and experiments can be designed to examine the requirement of particular inflammatory agents in eliciting specific deleterious responses after injury, e.g., cell death

Evaluation of objective vitritis grading method using optical coherence tomography: influence of phakic status and previous vitrectomy

PURPOSE: To evaluate a proposed method for objective measurement of vitreous inflammation using a spectral. domain optical coherence tomography (SD OCT) device in a large cohort of uveitis eyes, including pseudophakic eyes and vitrectomized eyes. DESIGN: Retrospective, observational cohort study. METHODS: One hundred five uveitis eyes (105 patients) with different vitreous haze score grades according to standardized protocols and corresponding SD OCT images (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, California, USA) were included. Clinical data recorded included phakic status, previous vitreoretinal surgery, and anterior chamber (AC) cells and flare. SD OCT images were analyzed using custom software that provided absolute measurements of vitreous (VIT) and retinal pigment epithelium (RPE) signal intensities, which were compared to generate a relative optical density ratio with arbitrary units (VIT/RPE-relative intensity) and compared to VHS. RESULTS: VIT/RPE-relative intensity showed a significant positive correlation with vitreous haze score (r = 0.535, P <.001) that remained significant after adjusting for factors governing media clarity, such as AC cells, AC flare, and phakic status (R-2-adjusted = 0.424, P <.001). Significant differences were also observed between the different vitreous haze score groups (P <.001). Preliminary observation did not observe differences in VIT/RPE-relative intensity values between phakic and pseudophakic eyes (0.3522 vs 0.3577, P =.48) and between nonvitrectomized and vitrectomized eyes (0.3540 vs 0.3580, P = .52), overall and respectively for each vitreous haze score subgroup. CONCLUSIONS: VIT/RPE-relative intensity values provide objective measurements of vitreous inflammation employing an SD OCT device. Phakic status and previous vitrectomy su