Global taxonomic, functional, and phylogenetic diversity of bees in apple orchards.

An essential prerequisite to safeguard pollinator species is characterisation of the multifaceted diversity of crop pollinators and identification of the drivers of pollinator community changes across biogeographical gradients. The extent to which intensive agriculture is associated with the homogenisation of biological communities at large spatial scales remains poorly understood. In this study, we investigated diversity drivers for 644 bee species/morphospecies in 177 commercial apple orchards across 33 countries and four global biogeographical biomes. Our findings reveal significant taxonomic dissimilarity among biogeographical zones. Interestingly, despite this dissimilarity, species from different zones share similar higher-level phylogenetic groups and similar ecological and behavioural traits (i.e. functional traits), likely due to habitat filtering caused by perennial monoculture systems managed intensively for crop production. Honey bee species dominated orchard communities, while other managed/manageable and wild species were collected in lower numbers. Moreover, the presence of herbaceous, uncultivated open areas and organic management practices were associated with increased wild bee diversity. Overall, our study sheds light on the importance of large-scale analyses contributing to the emerging fields of functional and phylogenetic diversity, which can be related to ecosystem function to promote biodiversity as a key asset in agroecosystems in the face of global change pressures.

Paternal obesity and its transgenerational effects on gastrointestinal function in male rat offspring.

The interplay between obesity and gastrointestinal (GI) motility is contradictory, and the transgenerational influence on this parameter is unknown. We aimed to evaluate the GI function in a model of paternal obesity and two subsequent generations of their male offspring. Newborn male rats were treated with monosodium glutamate (MSG) and composed the F1 generation, while control rats (CONT) received saline. At 90 days, male F1 were mated with non-obese females to obtain male offspring (F2), which later mated with non-obese females for obtaining male offspring of F3 generation. Lee Index analysis was adopted to set up the obesity groups. Alternating current biosusceptometry (ACB) technique was employed to calculate GI transit parameters: mean gastric emptying time (MGET), mean cecum arrival time (MCAT), mean small intestinal transit time (MSITT), and gastric frequency and amplitude of contractions. Glucose, insulin, and leptin levels and duodenal morphometry were measured. F1 obese rats showed a decrease in the frequency and amplitude of gastric contractions, while obese rats from the F2 generation showed accelerated MGET and delayed MCAT and MSITT. Glucose and leptin levels were increased in F1 and F2 generations. Insulin levels decreased in F1, F2, and F3 generations. Duodenal morphometry was altered in all three generations. Obesity may have paternal transgenerational transmission, and it provoked disturbances in the gastrointestinal function of three generations.

Paternal obesity and its transgenerational effects on gastrointestinal function in male rat offspring

The interplay between obesity and gastrointestinal (GI) motility is contradictory, and the transgenerational influence on this parameter is unknown. We aimed to evaluate the GI function in a model of paternal obesity and two subsequent generations of their male offspring. Newborn male rats were treated with monosodium glutamate (MSG) and composed the F1 generation, while control rats (CONT) received saline. At 90 days, male F1 were mated with non-obese females to obtain male offspring (F2), which later mated with non-obese females for obtaining male offspring of F3 generation. Lee Index analysis was adopted to set up the obesity groups. Alternating current biosusceptometry (ACB) technique was employed to calculate GI transit parameters: mean gastric emptying time (MGET), mean cecum arrival time (MCAT), mean small intestinal transit time (MSITT), and gastric frequency and amplitude of contractions. Glucose, insulin, and leptin levels and duodenal morphometry were measured. F1 obese rats showed a decrease in the frequency and amplitude of gastric contractions, while obese rats from the F2 generation showed accelerated MGET and delayed MCAT and MSITT. Glucose and leptin levels were increased in F1 and F2 generations. Insulin levels decreased in F1, F2, and F3 generations. Duodenal morphometry was altered in all three generations. Obesity may have paternal transgenerational transmission, and it provoked disturbances in the gastrointestinal function of three generations.

Phase transformation in the C form of myristic-acid crystals and DFT calculations.

In this study, the vibrational frequencies of myristic acid (CH3(CH2)12COOH) were obtained using density functional theory calculations, and the results were compared with experimental Raman and infrared data. Additionally, Raman spectra of crystalline myristic acid were recorded in the 300-20 K range. Raman spectroscopy gives important insights into the effect of low temperatures on its monoclinic phase. X-ray diffraction was performed from 298 to 133 K to provide additional information about the cryogenic behavior of the crystals. These undergo a phase transformation, which was confirmed by differential scanning calorimetry through an enthalpy anomaly observed at low temperatures. Raman spectra and X-ray diffraction refinement of the cell parameters in combination with differential scanning calorimetry at low temperatures revealed slight modifications, confirming a conformational change in the myristic acid molecules involving rearrangement of dimers within the unit cell.

ICTV Virus Taxonomy Profile: Dicistroviridae.

Dicistroviridae is a family of small non-enveloped viruses with monopartite, linear, positive-sense RNA genomes of approximately 8-10 kb. Viruses of all classified species infect arthropod hosts, with some having devastating economic consequences, such as acute bee paralysis virus in domesticated honeybees and taura syndrome virus in shrimp farming. Conversely, the host specificity and other desirable traits exhibited by several members of this group make them potential natural enemies for intentional use against arthropod pests, such as triatoma virus against triatomine bugs that vector Chagas disease. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Dicistroviridae which is available at www.ictv.global/report/dicistroviridae.

ICTV Virus Taxonomy Profile: Iflaviridae.

Iflaviridae is a family of small non-enveloped viruses with monopartite, positive-stranded RNA genomes of approximately 9-11 kilobases. Viruses of all classified species infect arthropod hosts, with the majority infecting insects. Both beneficial and pest insects serve as hosts, and infections can be symptomless (Nilaparvatalugens honeydew virus 1) or cause developmental abnormalities (deformed wing virus), behavioural changes (sacbrood virus) and premature mortality (infectious flacherie virus). The host range has not been examined for most members. The most common route of infection for iflaviruses is the ingestion of virus-contaminated food sources. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Iflaviridae, which is available at www.ictv.global/report/iflaviridae.

Association between subjective evaluation and physical parameters for radiographic images optimization.

PURPOSE: The purpose of this study was to develop a methodology to optimize computed radiographic techniques to image the skull, chest, and pelvis of a standard patient. METHODS: Optimization was performed by varying exposure levels with different tube voltages to generate images of an anthropomorphic phantom. Image quality was evaluated using visual grading analysis and measuring objective parameters such as the effective detective quantum efficiency and the contrast-to-noise ratio. Objective and subjective evaluations were compared to obtain an optimized technique for each anatomic region. RESULTS: Gold standard techniques provided a significant reduction in X-ray doses compared to the techniques used in our radiology service, without compromising diagnostic accuracy. They were chosen as follows 102 kVp/1.6 mAs for skull; 81 kVp/4.5 mAs for pelvis and 90 kVp/3.2 mAs for chest. CONCLUSION: There is a range of acceptable techniques that produce adequate images for diagnosis in computed radiography systems. This aspect allows the optimization process to be focused on the patient dose without compromising diagnostic capabilities. This process should be performed through association of quantitative and qualitative parameters, such as effective detective quantum efficiency, contrast-to-noise ratio, and visual grading analysis.

Alternate current biosusceptometry for the assessment of gastric motility after proximal gastrectomy in rats: a feasibility study.

BACKGROUND: This study proposes an experimental model to assess the consequences of gastric surgeries on gastric motility. We investigated the effects of proximal gastrectomy (PG) using a non-invasive technique (alternate current biosusceptometry [ACB]) on gastric contractility (GC), gastric emptying (GE), and orocecal transit (OCT) after the ingestion of liquids and solids in rats. METHODS: Twenty-four male rats were subjected to gastric motility assessment before and after the PG procedure. The GE and OCT results are expressed as the mean time of gastric emptying (MGET) and cecum arrival (MCAT). The GC recordings are presented as the frequency and amplitude of contractions. KEY RESULTS: Mean time of gastric emptying after solid meals were significantly different (p < 0.001) between control and PG (113 ± 5 to 99 ± 6 min). Mean time of cecum arrival ranged from 265 ± 9 to 223 ± 11 min (p < 0.001) and 164 ± 9 to 136 ± 17 min (p < 0.050) for solid and liquid meals, respectively. The assessment of GC showed that surgery decreased the phasic frequency (4.4 ± 0.4 to 3.0 ± 1.1 cpm, p < 0.050) and increased the amplitude of contractions (3.6 ± 2.7 to 7.2 ± 3.0 V/s, p < 0.050). No significant difference was found in tonic frequency. CONCLUSIONS & INFERENCES: The ACB system was able to assess GE, OCT, and GC in gastrectomized rats. Overall, PG accelerated GE and gastrointestinal transit, likely due to the increase in both intragastric pressure and amplitude contraction. Our data presented an efficient model to investigate functional consequences from gastric surgeries that will allow further studies involving different procedures.

Quality and dose optimization in hand computed radiography.

The objective of the present study was to optimize a radiographic technique for hand examinations using a computed radiography (CR) system and demonstrate the potential for dose reductions compared with clinically established technique. An exposure index was generated from the optimized technique to guide operators when imaging hands. Homogeneous and anthropomorphic phantoms that simulated a patient's hand were imaged using a CR system at various tube voltages and current settings (40-55 kVp, 1.25-2.8 mAs), including those used in clinical routines (50 kVp, 2.0 mAs) to obtain an optimized chart. The homogeneous phantom was used to assess objective parameters that are associated with image quality, including the signal difference-to-noise ratio (SdNR), which is used to define a figure of merit (FOM) in the optimization process. The anthropomorphic phantom was used to subjectively evaluate image quality using Visual Grading Analysis (VGA) that was performed by three experienced radiologists. The technique that had the best VGA score and highest FOM was considered the gold standard (GS) in the present study. Image quality, dose and the exposure index that are currently used in the clinical routine for hand examinations in our institution were compared with the GS technique. The effective dose reduction was 67.0%. Good image quality was obtained for both techniques, although the exposure indices were 1.60 and 2.39 for the GS and clinical routine, respectively.

Assessment of gastrointestinal motility in renal transplant recipients by alternate current biosusceptometry.

BACKGROUND: Gastrointestinal (GI) complications are common after renal transplantation, mainly owing to immunosuppressive therapy. Assessment of GI transit time can facilitate rational management of these disorders. OBJECTIVE: We evaluate the GI transit parameters in renal transplant recipients taking tacrolimus, azathioprine, and prednisone with the use of the alternate current biosusceptometry (ACB) technique and compared them with healthy volunteers. METHODS: Ten renal transplant recipients and 10 healthy volunteers were enrolled in this study. After an overnight fast, patients and volunteers ingested a standard meal containing magnetic markers. The biomagnetic monitoring was performed at 10-minute intervals for at least 8 hours to obtain gastric emptying as well as the colonic arrival time-intensity curves. Mean gastric emptying time (MGET), mean colon arrival time (MCAT), and mean small intestinal transit time (MSITT) were quantified and compared between control and patient groups with results expressed as mean ± SD. RESULTS: The MGET measured by the ACB technique was 48 ± 31 minutes and 197 ± 50 minutes for patients and healthy subjects, respectively. MSITT and MCAT values calculated for patients versus volunteers were 171 ± 71 minutes versus 197 ± 71 minutes and 219 ± 83 minutes versus 373 ± 52 minutes, respectively. Renal transplant recipients showed significantly faster; gastric emptying and colon arrival times (P < .001) compared with normal volunteers; however, small intestinal transit time was not significantly different (P = .44). CONCLUSIONS: In stable renal transplant recipients, the GI transit parameters were significantly faster than in normal healthy volunteers. ACB sensors are versatile technologies that can be used for clinical research, because they offer an excellent opportunity to evaluate GI transit in a noninvasive manner without the use of ionizing radiation.

Application of wavelets to the evaluation of phantom images for mammography quality control.

The main goal of this work was to develop a methodology for the computed analysis of American College of Radiology (ACR) mammographic phantom images, to be used in a quality control (QC) program of mammographic services. Discrete wavelet transform processing was applied to enhance the quality of images from the ACR mammographic phantom and to allow a lower dose for automatic evaluations of equipment performance in a QC program. Regions of interest (ROIs) containing phantom test objects (e.g., masses, fibers and specks) were focalized for appropriate wavelet processing, which highlighted the characteristics of structures present in each ROI. To minimize false-positive detection, each ROI in the image was submitted to pattern recognition tests, which identified structural details of the focalized test objects. Geometric and morphologic parameters of the processed test object images were used to quantify the final level of image quality. The final purpose of this work was to establish the main computational procedures for algorithms of quality evaluation of ACR phantom images. These procedures were implemented, and satisfactory agreement was obtained when the algorithm scores for image quality were compared with the results of assessments by three experienced radiologists. An exploratory study of a potential dose reduction was performed based on the radiologist scores and on the algorithm evaluation of images treated by wavelet processing. The results were comparable with both methods, although the algorithm had a tendency to provide a lower dose reduction than the evaluation by observers. Nevertheless, the objective and more precise criteria used by the algorithm to score image quality gave the computational result a higher degree of confidence. The developed algorithm demonstrates the potential use of the wavelet image processing approach for objectively evaluating the mammographic image quality level in routine QC tests. The implemented computational procedures could also enable the performance of advanced analyses to study potential dose reduction in a routine service.

Bioethanol production from Scenedesmus obliquus sugars: the influence of photobioreactors and culture conditions on biomass production.

A closed-loop vertical tubular photobioreactor (PBR), specially designed to operate under conditions of scarce flat land availability and irregular solar irradiance conditions, was used to study the potential of Scenedesmus obliquus biomass/sugar production. The results obtained were compared to those from an open-raceway pond and a closed-bubble column. The influence of the type of light source and the regime (natural vs artificial and continuous vs light/dark cycles) on the growth of the microalga and the extent of the sugar accumulation was studied in both PBRs. The best type of reactor studied was a closed-loop PBR illuminated with natural light/dark cycles. In all the cases, the relationship between the nitrate depletion and the sugar accumulation was observed. The microalga Scenedesmus was cultivated for 53 days in a raceway pond (4,500 L) and accumulated a maximum sugar content of 29 % g/g. It was pre-treated for carrying out ethanol fermentation assays, and the highest ethanol concentration obtained in the hydrolysate fermented by Kluyveromyces marxianus was 11.7 g/L.

Pre-treatment optimization of Scenedesmus obliquus microalga for bioethanol production.

The present work deals with the optimization of cellular disruption and sugar extraction from the microalgae Scenedesmus obliquus (Sc) for bioethanol production. Among the physical and physicochemical methods tested, the best results were obtained with acid hydrolysis by H(2)SO(4) (2N), at 120 °C for 30 min and using dried biomass. The sugar extraction efficiency level reached was 95.6% when compared to the harsh quantitative acid hydrolysis. The influence of other parameters such as biomass loading and number of extraction cycles were also evaluated. The results obtained in the latter case showed that a unique hydrolysis step is sufficient.

Validation of ACB in vitro and in vivo as a biomagnetic method for measuring stomach contraction.

BACKGROUND: The aim of this study was to validate a biomagnetic method (alternate current biosusceptometry, ACB) for monitoring gastric wall contractions in rats. METHODS: In vitro data were obtained to establish the relationship between ACB and the strain-gauge (SG) signal amplitude. In vivo experiments were performed in pentobarbital-anesthetized rats with SG and magnetic markers previously implanted under the gastric serosa or after ingestion of magnetic material. Gastric motility was quantified from the tracing amplitudes and frequency profiles obtained by Fast Fourier Transform. KEY RESULTS: The correlation between in vitro signal amplitudes was strong (R = 0.989). The temporal cross-correlation coefficient between the ACB and SG signal amplitude was higher (P < 0.0001) in the postprandial (88.3 ± 9.1 V) than in the fasting state (31.0 ± 16.9 V). Irregular signal profiles, low contraction amplitudes, and smaller signal-to-noise ratios explained the poor correlation between techniques for fasting-state recordings. When a magnetic material was ingested, there was also strong correlation in the frequency and signal amplitude and a small phase-difference between the techniques. The contraction frequencies using ACB were 0.068 ± 0.007 Hz (postprandial) and 0.058 ± 0.007 Hz (fasting) (P < 0.002) and those using SG were 0.066 ± 0.006 Hz (postprandial) and 0.059 ± 0.008 Hz (fasting) (P < 0.005). CONCLUSIONS & INFERENCES: In summary, ACB is reliable for monitoring gastric wall contractions using both implanted and ingested magnetic materials, and may serve as an accurate and sensitive technique for gastrointestinal motility studies.

Venereal and vertical transmission of deformed wing virus in honeybees (Apis mellifera L.).

Deformed wing virus (DWV) infected semen was used for artificial insemination of DWV-free virgin queens. High titres of DWV could subsequently be detected not only in the spermatheca, but also in the ovaries, demonstrating venereal transmission of DWV in honey bees. Subsequent vertical transmission of the virus to the progeny of DWV infected queens was also demonstrated. Neither transmission route is 100% effective. Whether venereal transmission of DWV occurs during natural mating remains to be determined. The implications for the use, sale and transport of semen samples for artificial insemination are discussed.

Scintigraphic validation of AC Biosusceptometry to study the gastric motor activity and the intragastric distribution of food in humans.

Abnormal intragastric distribution of food (IDF) and a phasic contractility in the proximal stomach have been related to dyspeptic symptoms. Thus, the behaviour of the stomach and the proximal region, in particular, continues to attract attention and demand for reliable and comfortable techniques. The aims of this study were to employ AC Biosusceptometry (ACB) and scintigraphy to evaluate IDF and gastric motor activity in humans. Fifteen healthy volunteers ingested 60 mL of yogurt containing 2 mCi of 99mTc and 4 g of ferrite. Each volunteer had gastric motility and IDF evaluated twice on separate days; on one occasion by ACB and another by scintigraphy. Digital signal processing was performed in MatLab (Mathworks Inc., Natick, MA, USA). Results were expressed as mean +/- SD. Similar results of distal accumulation time (P < 0.001) were obtained for scintigraphy (6.93 +/- 3.25 min) and for ACB (7.04 +/- 3.65 min). Fast Fourier Transform revealed two dominant frequencies (P > 0.9). Besides the well-know frequency of 3 cpm, our results showed identical frequencies in proximal stomach recordings (P < 0.001) for scintigraphic (1.01 +/- 0.01 cpm) and ACB (0.98 +/- 0.06 cpm). In summary, our data showed that scintigraphy and ACB are promising techniques to evaluate several aspects of gastric motility. Moreover, ACB is non-invasive, radiation-free and deserves the same importance as conventional methods for this kind of analysis.

A novel biomagnetic approach to study caecocolonic motility in humans.

Motility patterns play a major role in human colonic functions; however, its physiological significance is poorly understood. Several studies have been introducing the Alternating Current Biosusceptometry (ACB) as a valuable tool in gastroenterology and pharmaceutical research. Using gold standard techniques, great effort has been made to validate ACB as a method for measuring gastrointestinal motility in humans and animals. The aim of this study was to evaluate caecocolonic motility and its response to a meal in healthy volunteers. The results showed a dominant frequency of 3.17 +/- 0.13 cycles per minute (mean +/- SD) that remained unchanged even after a standardized meal (P > 0.01). The colonic response to a meal was recorded as a considerable increase in amplitude, reflected by motility index (P < 0.01) and was observed for all the volunteers. The caecocolonic motility could be assessed by the ACB providing new insights into physiological patterns of motility. Moreover, the method is non-invasive, radiation-free, cost-effective and independent of bowel preparation.

Testis structure and function in a nongenetic hyperadipose rat model at prepubertal and adult ages.

There are few data for hormonal levels and testis structure and function during postnatal development in rats neonatally treated with monosodium L-glutamate (MSG). In our study, newborn male pups were ip injected with MSG (4 mg/g body weight) every 2 d up to 10 d of age and investigated at prepubertal and adult ages. Plasma levels of leptin, LH, FSH, prolactin, testosterone (T), corticosterone, and free T4 (FT4) were measured. MSG rats displayed elevated circulating levels of corticosterone and hyperadiposity/hyperleptinemia, regardless of the age examined; conversely, circulating prolactin levels were not affected. Moreover, prepubertal MSG rats revealed a significant (P < 0.05) reduction in testis weight and the number of Sertoli (SC) and Leydig cells per testis. Leptin plasma levels were severalfold higher (2.41 vs. 8.07; P < 0.05) in prepubertal MSG rats, and these animals displayed plasma LH, FSH, T, and FT4 levels significantly decreased (P < 0.05). Taken together, these data indicate that testis development, as well as SC and Leydig cell proliferation, were disturbed in prepubertal MSG rats. Adult MSG rats also displayed significantly higher leptin plasma levels (7.26 vs. 27.04; P < 0.05) and lower (P < 0.05) LH and FSH plasma levels. However, T and FT4 plasma levels were normal, and no apparent alterations were observed in testis structure of MSG rats. Only the number of SCs per testis was significantly (P < 0.05) reduced in the adult MSG rats. In conclusion, although early installed hyperadipose/hyperleptinemia phenotype was probably responsible for the reproductive axis damages in MSG animals, it remains to be investigated whether this condition is the main factor for hypothalamus-pituitary-gonadal axis dysfunction in MSG rats.

Magnetic images of the disintegration process of tablets in the human stomach by ac biosusceptometry.

Oral administration of solid dosage forms is usually preferred in drug therapy. Conventional imaging methods are essential tools to investigate the in vivo performance of these formulations. The non-invasive technique of ac biosusceptometry has been introduced as an alternative in studies focusing on gastrointestinal motility and, more recently, to evaluate the behaviour of magnetic tablets in vivo. The aim of this work was to employ a multisensor ac biosusceptometer system to obtain magnetic images of disintegration of tablets in vitro and in the human stomach. The results showed that the transition between the magnetic marker and the magnetic tracer characterized the onset of disintegration (t(50)) and occurred in a short time interval (1.1 +/- 0.4 min). The multisensor ac biosusceptometer was reliable to monitor and analyse the in vivo performance of magnetic tablets showing accuracy to quantify disintegration through the magnetic images and to characterize the profile of this process.

AC biosusceptometry in the study of drug delivery.

Conventionally, pharmaceutical substances are administered orally because the gastrointestinal tract possesses the appropriate features for drug absorption. Nevertheless, the gastrointestinal tract physiology is complex and influenced by many factors. These factors must be completely understood for the optimization of oral drug delivery systems. Although in vitro tests provide information about release and drug absorption profiles, in vivo studies are essential, due to the biological variability. Several techniques have been employed in an attempt to conveniently characterize the behavior of solid dosage forms in vivo. The noninvasive biomagnetic technique of alternate current biosusceptometry (ACB) has been used in studies focusing on gastrointestinal motility and, more recently, to evaluate the performance of magnetic dosage forms. This article will discuss the main characteristics of AC biosusceptometry and its applicability for determination of the relationship between the human gastrointestinal tract and orally administered pharmaceutical dosage forms.