A global long-term daily reanalysis of reference evapotranspiration for drought and food-security monitoring.

NOAA has developed a global reference evapotranspiration (ET0) reanalysis using the UN Food and Agriculture Organization formulation (FAO-56) of the Penman-Monteith equation forced by MERRA phase 2 (MERRA2) meteorological and radiative drivers. The NOAA ET0 reanalysis is provided daily from January 1, 1980 to the near-present at a resolution of 0.5° latitude × 0.625° longitude. The reanalysis is verified against station data across southern Africa, a region presenting both significant challenges regarding hydroclimatic variability and observational quantity and quality and significant potential benefits to food-insecure populations. These data are generated from observations from the Southern African Science Service Centre for Climate Change and Adaptive Land Management (SASSCAL) network. We further verified globally against spatially distributed ET0 derived from two reanalyses-the Global Data Assimilation System (GDAS) and Princeton Global Forcing (PGF)-and these verifications produced similar results, yet demonstrated wide regional and seasonal differences. We also present cases that verify the operational applicability of the reanalysis in long-established drought, famine, crop- and pastoral-stress metrics, and in predictability assessments of drought forecasts.

Membrane-Freeze Concentration Hybrid for Temperature-Sensitive Biomolecules. Investigation, Application, and Techno-Economic Benefits.

In order to close the technology gap between membrane technologies and spray/freeze-drying ideally with a technology that avoids thermal stress to sensitive enzyme solutions, the limits of freeze concentration for this application have been investigated. On laboratory scale it was found that average crystal sizes are > 300 µm despite high viscosity and ice separation is possible up to 42 % solids and > 1000 mm2s-1 viscosity. No activity loss was observed during concentration. A combination of two-stage freeze concentration with a filter and wash column for ice liquid separation in an integrated setup with ultrafiltration has the greatest potential and was shown to be economically feasible in three out of four cases studied.

Factors influencing surgical outcome after anterior stabilization of the cervical spine with heterogeneous material.

Intervertebral fusion through an anterior approach with polymethylacrylate is a well-established neurosurgical technique in the treatment of cervical spine degeneration. However, questions still remain concerning the post-surgical outcome. Factors influencing surgical outcome that could help to predict which patients need further post-surgical treatment and what to expect after surgery are the subject of numerous studies. In the present study, we retrospectively collected data from patients who had undergone intervertebral fusion and defined which pre-operative factors could influence the surgical outcome. Between 1993 and 1997, 379 patients were surgically treated with the ventral fusion technique in our hospital. In 2006, we sent a questionnaire to the patients and 164 responses were received. We identified pre-operative presence of severe pain, hypesthesia, palsy and gait disturbance as negative predictive factors, whereas age, body mass index, pre-operative physical strain and the cervical segment involved did not seem to influence prognosis. In conclusion, identifying pre-operative factors which influence prognosis after intervetebral fusion will help predict postoperative outcome.

Anchoring effects in a wide binding pocket: the molecular basis of regioselectivity in engineered cytochrome P450 monooxygenase from B. megaterium.

The molecular basis of regioselectivity of cytochrome P450 monooxygenases from Bacillus megaterium (CYP102A1) with its flexible and widely opened active site is still not well understood. In the present work (-)-alpha-pinene bound complexes with two triple mutants were modeled to elucidate the contribution of the three major factors that mediate selectivity: active site shape, protein flexibility, and chemical reactivity of the substrate. For the triple mutant A74G F87V L188Q (GVQ), one stable, productive conformation of the substrate (conformation I) was identified by multiple molecular dynamics simulations. The model predicts pinene epoxide as a major product (42% pinene oxide, 23% verbenol) which is in agreement with the experimental product profile (70% pinene oxide, 20% verbenol). In contrast, for the triple mutant A74G F87G L188Q (GGQ) two stable productive substrate conformations were identified (conformations IIa and IIb), and verbenol was predicted as major product (81% verbenol, 16% myrtenol), which is in agreement with experimental results (77% verbenol, 10% myrtenol). The effect of chemical reactivity of the substrate was demonstrated by comparison of (-)-alpha-pinene to its regioisomer (-)-beta-pinene, where the product profile is shifted from 68% pinocarveol and 32% myrtanal in mutant GVQ, to 40% pinocarveol and 60% myrtanal in mutant GGQ. Our results strongly suggest a major role of residue 87 in anchoring (-)-alpha-pinene during substrate binding which provides a simple and elegant rationalization of the dynamic structure of this enzyme-substrate complex.

Diffusion of oriented single molecules with switchable mobility in networks of long unidimensional nanochannels.

Single dye molecules incorporated into a mesoporous matrix can act as highly sensitive reporters of their environment. Here, we use single TDI molecules incorporated as guests into hexagonal mesoporous films containing highly structured domains. The dye molecules allow us to map the size of these domains which can extend to over 100 microm. Investigation of the translational and orientational dynamics via single molecule fluorescence techniques gives structural as well as dynamical information about the host material. In an air atmosphere, the guest molecules show no movement but perfect orientation along the pore direction. The diffusion of the TDI molecules can be induced by placing the mesoporous film in a saturated atmosphere of chloroform. In single molecule measurements with very high positioning accuracy (down to 2-3 nm) the movement of molecules could be observed even between neighboring channels. This reveals the presence of defects like dead ends closing the pores or small openings in the silica walls between neighboring channels, where molecules can change from one channel to the next. A statistical analysis demonstrates that the diffusion of TDI in the mesoporous film cannot be described with a 1D-random diffusion but is more complicated due to the presence of adsorption sites in which the TDI molecules can be occasionally trapped.

Selective hydroxylation of highly branched fatty acids and their derivatives by CYP102A1 from Bacillus megaterium.

Highly branched fatty acids, the main components of the preen-gland waxes of the domestic goose and the Muscovy duck, and their derivatives are promising chiral precursors for the synthesis of macrolide antibiotics. The key step in the utilisation of these compounds is their regioselective hydroxylation, which cannot be achieved in a classical chemical approach. Three P450 monooxygenases, CYP102A1, CYP102A2 and CYP102A3, demonstrating high turnover numbers in the hydroxylation of iso and anteiso fatty acids (>400 min(-1)), were tested for their activity towards these substrates. CYP102A1 from Bacillus megaterium and its A74G F87V L188Q triple mutant hydroxylate a variety of these substrates with high activity and regioselectivity. In all cases, the triple mutant showed much higher activities than the wild-type enzyme. The binding constants, determined for wild-type CYP102A1 and the triple mutant with tetramethylnonanol as substrate, were >200 microM and approximately 23 microM, respectively. Data derived from binding analysis support the differences in activity found for the wild-type CYP102A1 and the triple mutant. Surprisingly, CYP102A2 and CYP102A3 from Bacillus subtilis did not show any activity. Substrate binding spectra, recorded to investigate substrate accessibility to the enzyme's active sites, revealed that the substrates either could not access the active site of the Bacillus subtilis monooxygenases, or did not come into proximity with the heme.

Measures of morbidity in clinical studies with recurrent skeletal complications.

Double-blind placebo-controlled clinical trials in metastatic bone disease considered counts of morbid events as the clinical outcome measure. These (recurrent) skeletal events were derived from a composite endpoint based on the necessity of medical interventions against bone pain or incident fractures. The trials were conducted for regulatory approval of therapy with bisphosphonates and were intended to demonstrate that an active treatment reduces the occurrence of skeletal events. The advanced morbidity of the patients led to a substantial amount of premature discontinuations, because of early death or because of progression of the basic disease. In some trials the discontinuations were unbalanced between treatment arms, where there were more dropouts under placebo. These effects contribute to a high portion of patients with no morbidity events. This background presents difficulties for the task of defining statistics that validly quantify skeletal morbidity in these trials while keeping the necessary simplicity so as to be accepted by health authorities and a clinical audience. Guided by this regulatory context, this paper compares the performance of five (simple) approaches to quantifying skeletal morbidity. Key criteria are bias and validity under different dropout scenarios, as well as the capability to demonstrate treatment effects. Based on theoretical considerations, two simulation studies, and real data results, a morbidity measure in the form of a smoothed rate was favored: this is a rate estimate in the individual patient of the form (y + c)(T + d)(-1), where y is the count of events, T is the patient's observation time, and c, d are constants to be appropriately chosen. This morbidity measure performed well in the simulation studies and showed a wanted insensitivity to dropout patterns. It outperforms the simple rate y/T due to the high portion of patients without events. Rates of this type were used before in the quantal bioassay and have a strong relationship to Bayesian approaches. Hence, these measures represent a good approach to handle the inherent difficulties of morbid event data in severely diseased patient populations, still offering sufficient simplicity.

Biochemical bone turnover markers are useful tools to assess changes in bone metabolism in marmosets.

This study was designed to investigate whether biochemical markers of bone resorption and formation could be determined in the serum and urine of marmosets (Callithrix jacchus), using standard laboratory chemistry methods and commercially available human kits. Consequently, the findings from this study will indicate whether the techniques and kits could serve as appropriate tools for assessing changes in bone turnover in this species. Two groups of animals (n = 12/group), consisting of a comparable number of young and old male and female marmosets, were given either isotonic saline or a single dose of the bisphosphonate ibandronate (0.1 mg/kg) s.c. in order to suppress bone turnover. Blood and urine were collected at baseline and 5 days after administration. Samples were analyzed for urinary (u) and serum (s) markers of bone formation (serum osteocalcin [sOC], serum N-terminal crosslinks of human pro-collagen type I [sP1NP]) and bone resorption (urinary pyridinoline [uPYD], urinary deoxypyridinoline [uDPD], serum C-terminal crosslinks of human collagen type I (C-telopeptide) [sCTX]), intact serum parathyroid hormone (iPTH) and urinary calcium and creatinine. Levels of all the markers of bone resorption and formation decreased during the study period. As expected, the bone formation markers decreased slightly less relative to the resorption markers. The most sensitive markers were sCTX (-33%; P < or =0.001) for bone resorption, and sP1NP (-3%; P < or =0.05) for bone formation. Serum PTH levels increased by 8% ( P < or =0.05), demonstrating a physiological reaction to prevent changes in serum calcium. Although not all variables reached statistical significance within the tested interval, the applied methods and kits were considered suitable for evaluating bone turnover changes in marmosets. Thus, these methods and kits can be utilized not only during the course of pharmacological investigations but also as additional tools to assess the overall bone health of this species.

Nanocrystalline tin as a preparative tool: synthesis of unprotected nanoparticles of SnTe and SnSe and a new route to (PhSe)4Sn.

The reactions of nanocrystalline tin metal (Sn*) with elemental selenium and tellurium and with the diaryldichalcogenides Ph2Se2 and Ph2Te2 have been investigated. Reaction of Sn* with the soluble tellurium source Ph2Te2 led to a clean formation of nanoparticles of cubic SnTe. Dependent on the concentration of Ph2Te2, the particles sizes could be varied between 15 and 60 nm in average, whereas the reaction of Sn* with Ph2Se2 formed molecular Sn(SePh)4 in high yield. The latter molecular compound was thermolyzed at 300 degrees C, yielding nanocrystalline SnSe with a broader distribution of size. The nanoparticles of SnTe were thoroughly investigated by transmission electron microscopy (TEM) and powder X-ray diffraction. The reactions of Sn* with elemental selenium and tellurium gave single- phase but microcrystalline SnSe and SnTe.