To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The gastrointestinal nematodes (GIN) stand out as an important cause of disease in small ruminant, especially on goat farm. Widespread resistance to synthetic anthelminthics has stimulated the research for alternative strategies of parasite control, including the use of medicinal plants. The present work summarizes the in vitro and in vivo studies of plants with activity against GIN of goats, focusing on the description of chemical constituents related to this effect. This review retrieved 56 scientific articles from 2008 to 2018 describing more than 100 different plant species. The most frequently investigated family was Fabaceae (30.7%). Most in vitro studies on the activity of plant extracts and fractions were carried out with of free-living stages nematodes. In vivo studies were conducted mainly with the use of plants in animal feed and generally showed lower effectiveness compared to in vitro assays. The main plant secondary metabolites associated with anthelmintic effect are condensed tannins, saponin and flavonoids. However, the studies with compounds isolated from plants and elucidation of their mechanisms of action are scarce. Herbal medicines are thought to be promising sources for the development of effective anthelmintic agents.
Digenea Carus, 1863 represent a highly diverse group of parasitic platyhelminths that infect all major vertebrate groups as definitive hosts. Morphology is the cornerstone of digenean systematics, but molecular markers have been instrumental in searching for a stable classification system of the subclass and in establishing more accurate species limits. The first comprehensive molecular phylogenetic tree of Digenea published in 2003 used two nuclear rRNA genes (ssrDNA = 18S rDNA and lsrDNA = 28S rDNA) and was based on 163 taxa representing 77 nominal families, resulting in a widely accepted phylogenetic classification. The genetic library for the 28S rRNA gene has increased steadily over the last 15 years because this marker possesses a strong phylogenetic signal to resolve sister-group relationships among species and to infer phylogenetic relationships at higher levels of the taxonomic hierarchy. Here, we have updated the database of 18S and 28S rRNA genes until December 2017, we have added newly generated 28S rDNA sequences and we have reassessed phylogenetic relationships to test the current higher-level classification of digeneans (at the subordinal and subfamilial levels). The new dataset consisted of 1077 digenean taxa allocated to 106 nominal families for 28S and 419 taxa in 98 families for 18S. Overall, the results were consistent with previous higher-level classification schemes, and most superfamilies and suborders were recovered as monophyletic assemblages. With the advancement of next-generation sequencing (NGS) technologies, new phylogenetic hypotheses from complete mitochondrial genomes have been proposed, although their power to resolve deep levels of trees remains controversial. Since data from NGS methods are replacing other widely used markers for phylogenetic analyses, it is timely to reassess the phylogenetic relationships of digeneans with conventional nuclear rRNA genes, and to use the new analysis to test the performance of genomic information gathered from NGS, e.g. mitogenomes, to infer higher-level relationships of this group of parasitic platyhelminths.
This article asks why some Indian districts experience chronic Maoist violence while others do not. The answer helps to explain India’s Maoist civil war, which is the product of the accumulation of violence in a few districts, as well as to generate a new hypothesis about the causes of civil war more generally. The authors argue that, other things equal, the emergence of subaltern-led parties at the critical juncture before armed organizations enter crowds them out: the stronger the presence of subaltern-led political parties in a district at this juncture, the lower the likelihood of experiencing chronic armed violence subsequently. They develop their argument through field research and test its main prediction using an original, district-level data set on subaltern incorporation and Maoist violence in India between 1967 and 2008. The article contributes a new, party-based explanation to the literatures on both civil war and Maoist violence in India. It also introduces new district-level data on the Maoist movement and on the incorporation of subaltern ethnic groups by political parties in India.
Land use law or zoning law (Derecho urbanístico, in Spanish, or Droit de l'urbanisme, in French) deals with the regulation ofland use. The regulation of urban planning is a part of that legal branch. Urban planning decides about the existence and situation of housing (including affordable housing), green areas, schools and other important infrastructures in the cities.
In this study, we undertake a dosimetric comparison of whole abdominal treatment plans of patients diagnosed with stage 3 Wilms tumour, to assess the benefits of treating these patients with volumetric arch therapy (VMAT) versus 3D conformal radiotherapy.
Material and methods
A retrospective study was undertaken on 23 patients receiving either VMAT or 3D conformal radiotherapy during 2013–2017. A dosimetric comparison was undertaken for both techniques, measuring planning target volume (PTV), conformity index (CI), homogeneity index (HI) and organs at risk (OAR).
The dosimetric parameters for the PTV dose in the VMAT and 3D conformal technique showed no statistical difference (1,289·17 cGy versus 1,357·13 cGy, respectively, p=0·404). However, the VMAT technique had a better CI (1·04 VMAT versus 1·26 3D, p=0·004), and there was little difference in the HI (1·13 VMAT versus 1·15 3D, p=0·1606). In the statistical analysis, the decrease in dose to OAR for the VMAT technique is statistically significant for doses to lung and kidney (p=0·011 and p=0·002, respectively). Between the two techniques, there was no statistical significance in dose difference to the other OAR.
This work proposes using the VMAT technique in whole abdominal irradiation to improve conformity, without affecting the quality of the PTV coverage, when compared with the 3D conformal technique. In addition, VMAT reduces the doses to OAR such as the remaining kidney and lungs that are important to preserve to reduce the probability of radiation toxicity in these patients.
Among fish parasitic nematodes Rhabdochona is one of the most speciose genera, with c. 100 species. Twelve congeneric species occur in Mexican freshwater fishes, in a region located between the Nearctic and Neotropical biogeographical regions. Host association and biogeographical history have determined the high species richness of Rhabdochona in Mexico. One of these species, Rhabdochona mexicana, is highly specific to the characid genus Astyanax. Characids are a group of freshwater fish with Neotropical affinity. In this paper, we explore the genetic diversity of R. mexicana through samples obtained from populations of Astyanax spp. across river basins of Mexico and Guatemala. Sequences of one mitochondrial and two ribosomal genes were obtained from 38 individuals and analysed using Maximum Likelihood and Bayesian Inference analysis. Phylogenetic analyses using cox1, and a concatenated alignment of 18S + 28S + cox1 recovered two genetic lineages. One of them corresponded with R. mexicana sensu stricto; this lineage included three reciprocally monophyletic subgroups; the other lineage was highly divergent and represented a putative candidate species. A detailed morphological study was conducted to corroborate the molecular findings. We describe a new species herein and discuss the implications of using molecular tools to increase our knowledge about the diversity of a speciose genus such as Rhabdochona.
Neoechinorhynchus is one of the most speciose genera of acanthocephalans, with approximately 116 described species. A recent study, aimed at establishing the genetic diversity of Neoechinorhynchus in Middle American freshwater fishes, validated nine species molecularly and morphologically and revealed the existence of 10 putative candidate species. Neoechinorhynchus golvani, a parasite commonly found in cichlids throughout Middle America with an allegedly large intraspecific morphological variability, was found to represent a species complex; species delimitation methods uncovered three additional genetic lineages. Here, we re-analyse the morphological and molecular data for N. golvani species complex infecting cichlids in that geographical area. A multivariate analysis of variance (MANOVA) was conducted particularly for the length of apical, middle and posterior hooks of the species/lineages of Neoechinorhynchus in cichlids, revealing morphological variation in the length of apical hooks for Lineage 8, although no morphological distinction was observed for Lineages 9 and 10. A new concatenated phylogenetic analysis of one mitochondrial and two ribosomal DNA genes was used to further corroborate the species delimitation among lineages; Neoechinorhynchus Lineage 8 was found to be morphologically and genetically distinct from its sister taxa, N. golvani and other two undescribed genetic lineages, and is formally described as a new species. Neoechinorhynchus costarricense n. sp. is described from the intestines of eight species of cichlids in Costa Rica. The new species is distinguished from the other species/lineages of Neoechinorhynchus in cichlids mainly by the size of the apical hooks of the proboscis.
The complex life cycle of Trichinella spiralis includes the migration of newborn larvae through the bloodstream to their encystment in muscle. The parasite establishes an intimate contact with the erythrocytes of the host both during the migration of the newborn larvae and when encysting, as this parasite causes intense vascularization in the muscle cell. The goal of this work was to study the effects of various concentrations of T. spiralis muscle larvae (ML) on erythrocyte membranes. The treatment was performed by incubating human erythrocytes with equal volume of different concentrations of ML for 30 minutes, with controlled agitation (37°C). The control erythrocytes (with no contact with the larvae) were incubated in the same way with an equal volume of physiological solution. To evaluate the alterations to the erythrocytes by the action of the larvae and in the respective controls, an Erythrocyte Rheometer and a Digital Image Analysis technique were used. The results indicated that when the larval concentration was higher, the aggregation and erythrocyte membrane alterations were also higher. Also, the erythrocyte deformability index and the erythrocyte elasticity increased. The values of isolated cell coefficient varied from 0.51 in the treatment with 100 larvae/ml to 0.91 in the incubation with 1000 larvae/ml. This experiment shows that T. spiralis muscle larvae affect significantly the red blood cell aggregation and the erythrocyte viscoelastic properties.
Emergency physicians are using bolus-dose vasopressors to temporize hypotensive patients until more definitive blood pressure support can be established. Despite a paucity of clinical outcome data, emergency department applications are expanding into the prehospital setting. This series presents two cases of field expedient vasopressor use by emergency medicine providers for preflight stabilization during aeromedical evacuation to a hospital ship as part of the United States Navy disaster response in Puerto Rico. A critical approach and review of the literature are discussed.
Two critically ill patients were managed in an austere environment as a result of the devastation from Hurricane Maria (Yabucoa, Puerto Rico; 2017). They both exhibited signs of respiratory distress, hemodynamic instability, and distributive shock requiring definitive airway management and hemodynamic support prior to aeromedical evacuation.
The novel use of field expedient vasopressors prior to induction for rapid sequence intubation was successfully and safely employed in both cases. Both patients had multiple risk factors for peri-induction cardiac arrest given their presenting hemodynamics. Despite their illness severity, both patients were induced, transported, and ultimately admitted to the intensive care unit (ICU) in stable condition following administration of the field expedient vasopressors.
Field expedient vasopressors were safely and effectively employed in an austere field environment during a disaster response. This case series contributes to the growing body of literature of safe bolus-dose vasopressor use by emergency physicians to temporize hypotensive patients in resource-constrained situations.
HardwickJM, MurnanSD, Morrison-PonceDP, DevlinJJ. Field Expedient Vasopressors During Aeromedical Evacuation: A Case Series from the Puerto Rico Disaster Response. Prehosp Disaster Med. 2018;33(6):668–672.
A thermoset polymer can be used for specific applications by creating a unique chemical composition that is designed for certain characteristic environments. To know the behavior of a thermoset polymer, it is necessary to thermally analyze its behavior during the curing process, as well as its mechanical behavior under certain loads that are applied in its field of application. In this study, the epoxy resin X was created at high temperatures, which there was no record of its thermal or mechanical behavior; the resin was analyzed to determine if it was possible to make a reduction in its curing cycle that was at temperature of 425° F with a time of 24 hours. As a result, through thermal analysis such as Differential Scanning Calorimetry (DSC), rheometry, Thermogravimetric Analysis (TGA) and Dynamic Mechanical Thermal Analysis (DMTA); as well as mechanical analysis, such as stress, hardness and planar cutting tests; it was possible to reduce the curing cycle of resin X, which is used in aerospace generators, from 24 hours at 425 ° F to 8 hours at 425 ° F. In the same way, this reduction of the cure cycle was verified by means of a qualification of a product that involved the reduction of the curing cycle of the epoxy resin obtaining very similar results to the original ones, verifying that the change of curing in the epoxy resin did not affected the functioning of the component. This methodology can be used and applied for the study of thermoset polymers that are used in several industries such as aerospace, automotive, among others.
We study both numerically and experimentally the steady cone-jet mode of electrospraying close to the stability limit of minimum flow rate. The leaky dielectric model is solved for arbitrary values of the relative permittivity and the electrohydrodynamic Reynolds number. The linear stability analysis of the base flows is conducted by calculating their global eigenmodes. The minimum flow rate is determined as that for which the growth factor of the dominant mode becomes positive. We find a good agreement between this theoretical prediction and experimental values. The analysis of the spatial structure of the dominant perturbation may suggest that instability originates in the cone-jet transition region, which shows the local character of the cone-jet mode. The electric relaxation time is considerably smaller than the residence time of a fluid particle in the cone-jet transition region (defined as the region where the surface and bulk intensities are of the same order of magnitude) except for the high-polarity case, where these characteristic times are commensurate with each other. The superficial charge is not relaxed within the cone-jet transition region except for the high-viscosity case, because significant inner electric fields arise in the cone-jet transition region. However, those electric fields are not large enough to invalidate the scaling laws that do not take them into account. Viscosity and polarization forces compete against the driving electric shear stress in the cone-jet transition region for small Reynolds numbers and large relative permittivities, respectively. Capillary forces may also play a significant role in the minimum flow rate stability limit. The experiments show the noticeable stabilizing effect of the feeding capillary for diameters even two orders of magnitude larger than that of the jet. Stable jets with electrification levels higher than the Rayleigh limit are produced. During the jet break-up, two consecutive liquid blobs may coalesce and form a bigger emitted droplet, probably due to the jet acceleration. The size of droplets exceeds Rayleigh’s prediction owing to the stabilizing effect of both the axial electric field and viscosity.
Patterns of genetic variation among populations can reveal the evolutionary history of species. Pinworm parasites are highly host specific and form strong co-evolutionary associations with their primate hosts. Here, we describe the genetic variation observed in four Trypanoxyuris species infecting different howler and spider monkey subspecies in Central America to determine if historical dispersal processes and speciation in the host could explain the genetic patterns observed in the parasites. Mitochondrial (cox1) and ribosomal (28S) DNA were analysed to assess genetic divergence and phylogenetic history of these parasites. Sequences of the 28S gene were identical within pinworms species regardless of host subspecies. However, phylogenetic analyses, haplotype relationships and genetic divergence with cox1 showed differentiation between pinworm populations according to host subspecies in three of the four Trypanoxyuris species analysed. Haplotype separation between host subspecies was not observed in Trypanoxyuris minutus, nor in Trypanoxyuris atelis from Ateles geoffoyi vellerosus and Ateles geoffoyi yucatanensis. Levels of genetic diversity and divergence in these parasites relate with such estimates reported for their hosts. This study shows how genetic patterns uncovered in parasitic organisms can reflect the host phylogenetic and biogeographic histories.