"The sterile insect technique (SIT) is an environment-friendly method of pest control that integrates well into area-wide integrated pest management (AW-IPM) programmes. This book takes a generic, ...thematic, comprehensive, and global approach in describing the principles and practice of the SIT. The strengths and weaknesses, and successes and failures, of the SIT are evaluated openly and fairly from a scientific perspective. The SIT is applicable to some major pests of plant-, animal-, and human-health importance, and criteria are provided to guide in the selection of pests appropriate for the SIT. In the second edition, all aspects of the SIT have been updated and the content considerably expanded. A great variety of subjects is covered, from the history of the SIT to improved prospects for its future application. The major chapters discuss the principles and technical components of applying sterile insects. The four main strategic options in using the SIT — suppression, containment, prevention, and eradication — with examples of each option are described in detail. Other chapters deal with supportive technologies, economic, environmental, and management considerations, and the socio-economic impact of AW-IPM programmes that integrate the SIT. In addition, this second edition includes six new chapters covering the latest developments in the technology: managing pathogens in insect mass-rearing, using symbionts and modern molecular technologies in support of the SIT, applying post-factory nutritional, hormonal, and semiochemical treatments, applying the SIT to eradicate outbreaks of invasive pests, and using the SIT against mosquito vectors of disease. This book will be useful reading for students in animal-, human-, and plant-health courses. The in-depth reviews of all aspects of the SIT and its integration into AW-IPM programmes, complete with extensive lists of scientific references, will be of great value to researchers, teachers, animal-, human-, and plant-health practitioners, and policy makers."
In molecular phylogenetics, it is typically assumed that the evolutionary process for DNA can be approximated by independent and identically distributed Markovian processes at the variable sites and ...that these processes diverge over the edges of a rooted bifurcating tree. Sometimes the nucleotides are transformed from a 4-state alphabet to a 3- or 2-state alphabet by a procedure that is called recoding, lumping, or grouping of states. Here, we introduce a likelihood-ratio test for lumpability for DNA that has diverged under different Markovian conditions, which assesses the assumption that the Markovian property of the evolutionary process over each edge is retained after recoding of the nucleotides. The test is derived and validated numerically on simulated data. To demonstrate the insights that can be gained by using the test, we assessed two published data sets, one of mitochondrial DNA from a phylogenetic study of the ratites and the other of nuclear DNA from a phylogenetic study of yeast. Our analysis of these data sets revealed that recoding of the DNA eliminated some of the compositional heterogeneity detected over the sequences. However, the Markovian property of the original evolutionary process was not retained by the recoding, leading to some significant distortions of edge lengths in reconstructed trees.Evolutionary processes; likelihood-ratio test; lumpability; Markovian processes; Markov models; phylogeny; recoding of nucleotides..
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Spatial regulation is often encountered as a component of multi-tiered regulatory systems in eukaryotes, where processes are readily segregated by organelle boundaries. Well-characterized examples of ...spatial regulation are less common in bacteria. Low-fidelity DNA polymerase V (UmuD'2C) is produced in Escherichia coli as part of the bacterial SOS response to DNA damage. Due to the mutagenic potential of this enzyme, pol V activity is controlled by means of an elaborate regulatory system at transcriptional and posttranslational levels. Using single-molecule fluorescence microscopy to visualize UmuC inside living cells in space and time, we now show that pol V is also subject to a novel form of spatial regulation. After an initial delay (~ 45 min) post UV irradiation, UmuC is synthesized, but is not immediately activated. Instead, it is sequestered at the inner cell membrane. The release of UmuC into the cytosol requires the RecA* nucleoprotein filament-mediated cleavage of UmuD→UmuD'. Classic SOS damage response mutants either block umuD(K97A) or constitutively stimulate recA(E38K) UmuC release from the membrane. Foci of mutagenically active pol V Mut (UmuD'2C-RecA-ATP) formed in the cytosol after UV irradiation do not co-localize with pol III replisomes, suggesting a capacity to promote translesion DNA synthesis at lesions skipped over by DNA polymerase III. In effect, at least three molecular mechanisms limit the amount of time that pol V has to access DNA: (1) transcriptional and posttranslational regulation that initially keep the intracellular levels of pol V to a minimum; (2) spatial regulation via transient sequestration of UmuC at the membrane, which further delays pol V activation; and (3) the hydrolytic activity of a recently discovered pol V Mut ATPase function that limits active polymerase time on the chromosomal template.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A pilot study among farming households in eastern Iowa was conducted to assess human exposure to neonicotinoids (NEOs). The study was in a region with intense crop and livestock production and where ...groundwater is vulnerable to surface-applied contaminants. In addition to paired outdoor (hydrant) water and indoor (tap) water samples from private wells, urine samples were collected from 47 adult male pesticide applicators along with the completions of dietary and occupational surveys. Estimated Daily Intake (EDI) were then calculated to examine exposures for different aged family members. NEOs were detected in 53% of outdoor and 55% of indoor samples, with two or more NEOs in 13% of samples. Clothianidin was the most frequently detected NEO in water samples. Human exposure was ubiquitous in urine samples. A median of 10 different NEOs and/or metabolites were detected in urine, with clothianidin, nitenpyram, thiamethoxam, 6-chloronicotinic acid, and thiacloprid amide detected in every urine samples analyzed. Dinotefuran, imidaclothiz, acetamiprid-N-desmethyl, and N-desmethyl thiamethoxam were found in ≥70% of urine samples. Observed water intake for study participants and EDIs were below the chronic reference doses (CRfD) and acceptable daily intake (ADI) standards for all NEOs indicating minimal risk from ingestion of tap water. The study results indicate that while the consumption of private well tap water provides a human exposure pathway, the companion urine results provide evidence that diet and/or other exposure pathways (e.g., occupational, house dust) may contribute to exposure more than water contamination. Further biomonitoring research is needed to better understand the scale of human exposure from different sources.
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•Neonicotinoids prevalent in aquifers vulnerable to surface-applied contaminants.•Neonicotinoids were ubiquitously detected (median = 10) in farmer's urine samples.•Consumption of well water only partially explains the urine neonicotinoid results.•Diet is likely an important factor contributing to the urine neonicotinoid results.
Selection and soft-landing of bionanoparticles in vacuum is potentially a preparative approach to separate heterogeneous mixtures for high-resolution structural study or to deposit homogeneous ...materials for nanotechnological applications. Soft-landing of intact protein assemblies however remains challenging, due to the difficulties of manipulating these heavy species in mass-selective devices and retaining their structure during the experiment. We have developed a tandem mass spectrometer with the capability for controlled ion soft-landing and ex situ visualization of the soft-landed particles by means of transmission electron microscopy. The deposition conditions can be controlled by adjusting the kinetic energies of the ions by applying accelerating or decelerating voltages to a set of ion-steering optics. To validate this approach, we have examined two cage-like protein complexes, GroEL and ferritin, and studied the effect of soft-landing conditions on the method’s throughput and the preservation of protein structure. Separation, based on mass-to-charge ratio, of holo- and apo-ferritin complexes after electrospray ionization enabled us to soft-land independently the separated complexes on a grid suitable for downstream transmission electron microscopy analysis. Following negative staining, images of the soft-landed complexes reveal that their structural integrity is largely conserved, with the characteristic central cavity of apoferritin, and iron core of holoferritin, surviving the phase transition from liquid to gas, soft-landing, and dehydration in vacuum.
Objective
The aim of this study was to investigate the cognitive effects of unilateral directional versus ring subthalamic nucleus deep brain stimulation (STN DBS) in patients with advanced ...Parkinson's disease.
Methods
We examined 31 participants who underwent unilateral STN DBS (left n = 17; right n = 14) as part of an National Institutes of Health (NIH)‐sponsored randomized, double‐blind, crossover study contrasting directional versus ring stimulation. All participants received unilateral DBS implants in the hemisphere more severely affected by motor parkinsonism. Measures of cognition included verbal fluency, auditory‐verbal memory, and response inhibition. We used mixed linear models to contrast the effects of directional versus ring stimulation and implant hemisphere on longitudinal cognitive function.
Results
Crossover analyses showed no evidence for group‐level changes in cognitive performance related to directional versus ring stimulation. Implant hemisphere, however, impacted cognition in several ways. Left STN participants had lower baseline verbal fluency than patients with right implants (t 20.66 = −2.50, p = 0.02). Verbal fluency declined after left (p = 0.013) but increased after right STN DBS (p < 0.001), and response inhibition was faster following right STN DBS (p = 0.031). Regardless of hemisphere, delayed recall declined modestly over time versus baseline (p = 0.001), and immediate recall was unchanged.
Interpretation
Directional versus ring STN DBS did not differentially affect cognition. Similar to prior bilateral DBS studies, unilateral left stimulation worsened verbal fluency performance. In contrast, unilateral right STN surgery increased performance on verbal fluency and response inhibition tasks. Our findings raise the hypothesis that unilateral right STN DBS in selected patients with predominant right brain motor parkinsonism could mitigate declines in verbal fluency associated with the bilateral intervention. ANN NEUROL 2024;95:1205–1219
Collision-induced dissociation (CID) is the dominant method for probing intact macromolecular complexes in the gas phase by means of mass spectrometry (MS). The energy obtained from collisional ...activation is dependent on the charge state of the ion and the pressures and potentials within the instrument: these factors limit CID capability. Activation by infrared (IR) laser radiation offers an attractive alternative as the radiation energy absorbed by the ions is charge-state-independent and the intensity and time scale of activation is controlled by a laser source external to the mass spectrometer. Here we implement and apply IR activation, in different irradiation regimes, to study both soluble and membrane protein assemblies. We show that IR activation using high-intensity pulsed lasers is faster than collisional and radiative cooling and requires much lower energy than continuous IR irradiation. We demonstrate that IR activation is an effective means for studying membrane protein assemblies, and liberate an intact V-type ATPase complex from detergent micelles, a result that cannot be achieved by means of CID using standard collision energies. Notably, we find that IR activation can be sufficiently soft to retain specific lipids bound to the complex. We further demonstrate that, by applying a combination of collisional activation, mass selection, and IR activation of the liberated complex, we can elucidate subunit stoichiometry and the masses of specifically bound lipids in a single MS experiment.
Nanoparticles agglomerate and clump in solution, making it difficult to accurately deliver them for in vivo or in vitro experiments. Thus, experiments were conducted to determine the best method to ...suspend nanosized particles. Ultrafine and fine carbon black and titanium dioxide were suspended in phosphate buffered saline (PBS), rat and mouse bronchoalveolar lavage fluid (BALF), and PBS containing dipalmitoyl phosphatidylcholine (DPPC) and/or mouse serum albumin. To assess and compare how these various suspension media dispersed the nanoparticles, images were taken using light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results of this study show that PBS is not a satisfactory medium to prepare nanoparticle suspensions. However, BALF was an excellent media in which to suspend nanoparticles. The use of PBS containing protein or DPPC alone, in concentrations found in BALF, did not result in satisfactory particle dispersion. However, PBS-containing protein plus DPPC was satisfactory, although less effective than BALF.
Purpose Potassium citrate therapy has become one of the cornerstones of medical stone management. We elucidated the long-term effects of potassium citrate on urinary metabolic profiles and its impact ...on stone formation rates. Materials and Methods We performed a retrospective cohort study in patients treated at the Comprehensive Kidney Stone Center at our institution between 2000 and 2006. Patients with pre-therapy and post-therapy 24-hour urinary profiles available who remained on potassium citrate for at least 6 months were included in the analysis. Results Of the 1,480 patients with 24-hour urinary profiles 503 met study inclusion criteria. Mean therapy duration was 41 months (range 6 to 168). Overall a significant and durable change in urinary metabolic profiles was noted as soon as 6 months after the onset of therapy. These changes included increased urinary pH (5.90 to 6.46, p <0.0001) and increased urinary citrate (470 to 700 mg a day, p <0.0001). The stone formation rate also significantly decreased after the initiation of potassium citrate from 1.89 to 0.46 stones per year (p <0.0001). There was a 68% remission rate and a 93% decrease in the stone formation rate. Conclusions Potassium citrate provides a significant alkali and citraturic response during short-term and long-term therapy with the change in urinary metabolic profiles sustained as long as 14 years of treatment. Moreover, long-term potassium citrate significantly decreases the stone formation rate, confirming its usefulness in patients with recurrent nephrolithiasis.
The Clp protease is conserved among eubacteria and most eukaryotes, and uses ATP to drive protein substrate unfolding and translocation into a chamber of sequestered proteolytic active sites. To ...investigate the proteolytic core of the ClpXP1/P2 protease from the cyanobacterium Synechococcus elongatus we have used a non-denaturing mass spectrometry approach. We show that the proteolytic core is a double ring tetradecamer consisting of an equal number of ClpP1 and ClpP2 subunits with masses of 21.70 and 23.44kDa, respectively. Two stoichiometries are revealed for the heptameric rings: 4ClpP1+3ClpP2 and 3ClpP1+4ClpP2. When combined in the double ring the stoichiometries are (4ClpP1+3ClpP2)+(3ClpP1+4ClpP2) and 2×(3ClpP1+4ClpP2) with a low population of a 2×(4ClpP1+3ClpP2) tetradecamer. The assignment of the stoichiometries is confirmed by collision-induced dissociation of selected charge states of the intact heptamer and tetradecamer. Presence of the heterodimers, heterotetramers and heterohexamers, and absence of the mono-oligomers, in the mass spectra of the partially denatured protease indicates that the ring complex consists of a chain of ClpP1/ClpP2 heterodimers with the ring completed by an additional ClpP1 or ClpP2 subunit.
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