Rethinking False Spring Risk

Temperate plants are at risk of being exposed to late spring freezes. These freeze events - often called false springs - are one of the strongest factors determining temperate plants species range limits and can impose high ecological and economic damage. As climate change may alter the prevalence and severity of false springs, our ability to forecast such events has become more critical, and it has led to a growing body of research. Many false spring studies largely simplify the myriad complexities involved in assessing false spring risks and damage. While these studies have helped advance the field and may provide useful estimates at large scales, studies at the individual to community levels must integrate more complexity for accurate predictions of plant damage from late spring freezes. Here we review current metrics of false spring, and how, when and where plants are most at risk of freeze damage. We highlight how life stage, functional group, species differences in morphology and phenology, and regional climatic differences contribute to the damage potential of false springs. More studies aimed at understanding relationships among species tolerance and avoidance strategies, climatic regimes, and the environmental cues that underlie spring phenology would improve predictions at all biological levels. An integrated approach to assessing past and future spring freeze damage would provide novel insights into fundamental plant biology, and offer more robust predictions as climate change progresses, which is essential for mitigating the adverse ecological and economic effects of false springs

Water Use Efficiency in Chilean and Argentine Humid Temperate Grass-Legume Pastures

At two sites in Argentina and Chile five levels of water input were applied to four sown pastures of varying ages during spring and summer. The pastures consisted principally of C3 grasses and legumes, some of which were sown such as Lolium perenne, Trifolium repens, Dactylis glomerata. Dry matter (DM) production was measured and related to the estimated total evapotranspiration (ET): responses were both highly linear. Both responses to ET and absolute yields were higher at the Argentinian than at the Chilean site: respectively 10.7 and 15.2 kg DM/mm water evapotranspired. Nevertheless the calculated indices of sensitivity (Ky) of Doorenbos and Kassam (1979) were similar for the two sites, indicating a similar priority for irrigation in terms of expected responses

Combination therapy with rituximab, low-dose cyclophosphamide, and prednisone for idiopathic membranous nephropathy: a case series

BACKGROUND: Membranous nephropathy is a common cause of the nephrotic syndrome. Treatment with standard regimens fails to induce complete remission in most patients. We evaluated the efficacy of combination therapy with rituximab, low-dose, oral cyclophosphamide, and an accelerated prednisone taper (RCP) for the treatment of idiopathic membranous nephropathy. METHODS: We analyzed 15 consecutive patients with idiopathic membranous nephropathy treated with RCP at Massachusetts General Hospital. Seven patients (47%) received RCP as initial therapy, and the other eight patients (53%) received RCP for relapsing or refractory disease. All patients had at least 1 year of follow-up. The co-primary outcomes were attainment of partial and complete remission. Partial remission was defined as a urinary protein to creatinine ratio (UPCR) < 3 g/g and a 50% reduction from baseline. Complete remission was defined as a UPCR < 0.3 g/g. Secondary outcomes were serious adverse events and the change in proteinuria, serum creatinine, serum albumin, cholesterol, triglycerides, and immunoglobulin G levels after 1 year of treatment. RESULTS: Over a median follow-up time of 37 (IQR, 34-44) months, 100% of patients achieved partial remission and 93% of patients achieved complete remission at a median time of 2 and 13 months, respectively. After 1 year of treatment, median (IQR) UPCR declined from 8.2 (6.6-11.1) to 0.3 (0.2-0.7) g/g (P < 0.001). Three serious adverse events occurred over 51 patient years. No patients died or progressed to ESKD. CONCLUSIONS: Treatment of idiopathic membranous nephropathy with RCP resulted in high rates of complete remission. Larger studies evaluating this regimen are warranted

Numerical simulations of thixotropic semi-solid aluminium alloys in open-rotor and rotor-stator mixers

This research uses the Bautista-Manero-Puig (BMP) model to examine flow patterns of semi-solid aluminium alloys (Al) in open-rotor and stator-rotor mixers via numerical solutions. The model captures the distinct thixo-viscoelastic behavior of the Al-alloys at low temperatures, near melting point. The analysis involves using 2D structured-meshes for open-rotor and rotor-stator geometries. Solutions for Newtonian and thixo-viscoelastic model fluids are reported through fields of velocity, strain-rate, stress, fluidity, and streamlines, revealing distinct features. Findings reveal nonlinear thixo-viscoelastic vortex patterns that vary with rotational speed, resulting in different fluidity and stress profiles compared to the invariant response of Newtonian fluids. At lower rotational speeds, rotor-pallets are dominated by structured material that gradually becomes unstructured to cover the outer vessel walls. When including a stator, the inner stator region resembles the Newtonian solution, but the outflow through stator gaps is reduced due to flow-structure levels outside. This information is of interest for industrial design and optimization of molten Al-alloy processing.Programa de Transferencia de Tecnología de la DFB FEDER Consejo Nacional de Ciencias, Humanidades y Tecnologı́as (CONAHCYT, Mexico) Universidad Nacional Autónoma de México UNA

Hepatoprotection and neuroprotection induced by low doses of IGF-II in aging rats

<p>Abstract</p> <p>Background</p> <p>GH and IGFs serum levels decline with age. Age-related changes appear to be associated to decreases in these anabolic hormones. We have previously demonstrated that IGF-I replacement therapy improves insulin resistance, lipid metabolism and reduces oxidative damage (in brain and liver) in aging rats. Using the same experimental model, the aim of this work was to study whether the exogenous administration of IGF-II, at low doses, acts analogous to IGF-I in aging rats.</p> <p>Methods</p> <p>Three experimental groups were included in this study: young healthy controls (yCO, 17 weeks old); untreated old rats (O, 103 weeks old); and aging rats treated with IGF-II (O+IGF-II, 2 μg * 100 g body weight^-1* day^-1) for 30 days. Analytical parameters were determined in serum by routine laboratory methods using an autoanalyzer (Cobas Mira; Roche Diagnostic System, Basel, Switzerland). Serum levels of hormones (testosterone, IGF-I and insulin) were assessed by RIA. Serum Total Antioxidant Status was evaluated using a colorimetric assay. Mitochondrial membrane potential was evaluated using rhodamine 123 dye (adding different substrates to determine the different states). ATP synthesis in isolated mitochondria was determined by an enzymatic method.</p> <p>Results</p> <p>Compared with young controls, untreated old rats showed a reduction of IGF-I and testosterone levels with a decrease of serum total antioxidant status (TAS). IGF-II therapy improved serum antioxidant capability without modifying testosterone and IGF-I circulating concentrations. In addition, IGF-II treatment reduced oxidative damage in brain and liver, improving antioxidant enzyme activities and mitochondrial function. IGF-II was also able to reduce cholesterol and triglycerides levels increasing free fatty acids concentrations.</p> <p>Conclusions</p> <p>We demonstrate that low doses of IGF-II induce hepatoprotective, neuroprotective and metabolic effects, improving mitochondrial function, without affecting testosterone and IGF-I levels.</p

Altered liver gene expression in CCl4-cirrhotic rats is partially normalized by insulin-like growth factor-I

We have previously shown that the administration of low doses of insulin-like growth factor-I (IGF-I) to CCl4-cirrhotic rats improves liver function and reduces fibrosis. To better understand the mechanisms behind the hepatoprotective effects of IGF-I, and to identify those genes whose expression is affected in cirrhosis and after IGF-1 treatment, we have performed differential display of mRNA analysis by means of polymerase chain reaction (PCR) in livers from control and CCl4-cirrhotic rats treated or not with IGF-I. We have identified 16 genes that were up- or down-regulated in the cirrhotic liver. IGF-I treatment partially normalized the expression of eight of these genes, including serine proteinase inhibitors such as serpin-2 and alpha-1-antichymotripsin, alpha-1-acid glycoprotein, and alpha-2u-globulin. Additionally, we show that IGF-I enhanced the regenerative activity in the cirrhotic liver, as determined by the increased expression of the proliferating cell nuclear antigen (PCNA). Finally, IGF-I treatment partially restored the expression of growth hormone receptor (GHR) and the levels of global genomic DNA methylation, which are reduced in human and experimental cirrhosis. Taken together, our observations confirm the hepatoprotective effects of IGF-I, and suggest that this action can be exerted in part through the normalization of liver gene expression, growth hormone (GH) responsiveness and global genomic DNA methylation