Theileriosis in naturally infected roan antelope (Hippotragus equinus).

Cases of Theileria-associated mortality are rarely reported in African wild artiodactyls. Descriptions of lesions are limited, particularly in endangered hippotraginids. Here, we analyzed retrospectively the gross and histologic findings in 55 roan antelope (Hippotragus equinus) with fatal natural theileriosis. The most frequently recorded gross findings in 40 cases were widespread petechiae and ecchymoses (72.5%), probable anemia (67.5%), icterus (60%), splenomegaly (60%), hepatomegaly (52.5%), and pulmonary edema (50%). Histologic lesions in 34 cases were characterized by multi-organ infiltrates of parasitized and nonparasitized mononuclear leukocytes (MLs), and fewer multinucleate giant cells (MNGCs). Liver, lung, kidney, adrenal gland, and heart were most consistently infiltrated, followed by spleen and lymph nodes. Leukocytes were phenotyped in lung, liver, kidney, and heart specimens from 16 cases, using immunohistochemistry to detect CD20, CD3, myeloid/histiocyte antigen (MAC387), IBA-1, and CD204 surface receptors. A roan polyclonal anti-Theileria sp. (sable) antibody was applied to the same tissues to identify intraleukocytic parasite antigens. Similar proportions of intravascular and extravascular IBA-1-, CD204-, and MAC387-reactive putative monocyte-macrophages and fewer CD3-positive putative T-lymphocytes were identified in all organs, especially the lungs in infected roan. CD20-positive putative B-lymphocytes were significantly scarcer than in uninfected controls. Intraleukocytic Theileria parasites labeled consistently in affected tissues. Some parasitized and nonparasitized MLs and the MNGCs failed to label with selected leukocyte markers. Fatal theileriosis in roans may largely be the result of multi-organ monocyte-macrophage activation with associated tissue injury and overwhelming systemic inflammation. The identity of the parasitized leukocytes and characteristics of the lymphohistiocytic response require further clarification in roans.

The Pathology of Pathogenic Theileriosis in African Wild Artiodactyls.

The published literature on schizont-"transforming," or pathogenic theileriosis, in African wild artiodactyls is dated and based on limited information. Here the authors review the taxonomy, diagnosis, epidemiology, hematology, pathology, and aspects of control in various species. Molecular studies based on 18S and 16S rRNA gene sequences have shown that African wild artiodactyls are commonly infected with diverse Theileria spp., as well as nontheilerial hemoprotozoa and rickettsia-like bacteria, and coinfections with pathogenic and nonpathogenic Theileria species are often recorded. Although theileriosis is still confusingly referred to as cytauxzoonosis in many species, the validity of a separate Cytauxzoon genus in artiodactyls is debated. The epidemiology of theileriosis is complex; the likelihood of fatal disease depends on the interplay of parasite, vertebrate host, tick vector, and environmental factors. Roan calves (Hippotragus equinus) and stressed animals of all host species are more susceptible to fatal theileriosis. Even though regenerative anemia is common, peripheral blood piroplasm parasitemia does not correlate with disease severity. Other than anemia, common macroscopic lesions include icterus, hemorrhages (mucosal, serosal, and tissue), fluid effusions into body cavities, lung edema, and variably sized raised cream-colored foci of leukocyte infiltration in multiple organs. Histopathologic findings include vasocentric hyperproliferation and lysis of atypical leukocytes with associated intracellular schizonts, parenchymal necrosis, hemorrhage, thromboembolism, and edema. Immunophenotyping is required to establish the identity of the schizont-transformed leukocytes in wild ungulates. Throughout the review, we propose avenues for future research by comparing existing knowledge on selected aspects of theileriosis in domestic livestock with that in African wild artiodactyls.

Stabilized Vanadium Catalyst for Olefin Polymerization by Site Isolation in a Metal-Organic Framework.

Vanadium catalysts offer unique selectivity in olefin polymerization, yet are underutilized industrially owing to their poor stability and productivity. Reported here is the immobilization of vanadium by cation exchange in MFU-4l, thus providing a metal-organic framework (MOF) with vanadium in a molecule-like coordination environment. This material forms a single-site heterogeneous catalyst with methylaluminoxane and provides polyethylene with low polydispersity (PDI≈3) and the highest activity (up to 148 000 h-1 ) reported for a MOF-based polymerization catalyst. Furthermore, polyethylene is obtained as a free-flowing powder as desired industrially. Finally, the catalyst shows good structural integrity and retains polymerization activity for over 24 hours, both promising attributes for the commercialization of vanadium-based polyolefins.

Photoresponsive gels prepared by ring-opening metathesis polymerization.

This communication describes photoresponsive gels, prepared using ring-opening metathesis polymerization (ROMP), that dissolve upon irradiation with ultraviolet light. Exposure of mixtures of norbornene-type ROMP monomers and new photoreactive cross-linkers comprising two norbornene units bound through a chain containing o-nitrobenzyl esters (NBEs) to well-known ruthenium carbene catalysts gave cross-linked polymer networks that swelled in organic solvents or water depending on the structure of the monomer. These gels became homogeneous upon irradiation with UV light, consistent with breaking of the cross-links through photolysis of the NBE groups. The irradiation time required for homogenization of the gels depended on the cross-link density and the structure of the photoresponsive cross-linker.

Leveraging a smartphone to perform time-gated luminescence measurements.

Empowered by advanced on-board sensors, high-performance optics packages and ever-increasing computational power, smartphones have democratized data generation, collection, and analysis. Building on this capacity, many platforms have been developed to enable its use as an optical sensing platform for colorimetric and fluorescence measurements. In this paper, we report the ability to enable a smartphone to perform laboratory quality time-resolved analysis of luminescent samples via the exploitation of the rolling shutter mechanism of the native CMOS imager. We achieve this by leveraging the smartphone's standard image capture applications, commercially available image analysis software, and housing the device within a UV-LED containing case. These low-cost modifications enable us to demonstrate the smartphone's analytical potential by performing tasks ranging from authentication and encryption to the interrogation of packaging, compounds, and physical phenomena. This approach underscores the power of repurposing existing technologies to extend the reach and inclusivity of scientific exploration, opening new avenues for data collection and analysis.

Clinical and hematologic features of experimental theileriosis in roan calves (Hippotragus equinus).

Theileria sp. (sable) infection commonly causes significant calf mortality in endangered roan antelopes (Hippotragus equinus). Schizont-induced leukocyte transformation and systemic immune dysregulation with associated cytopenias characterizes theileriosis in livestock. Data on related hematologic alterations are scarce in roan antelopes. The objective of this study was to investigate temporal changes in selected clinical parameters and hematologic measurands in experimentally infected (EI) roan calves. Six of eight calves developed theileriosis after inoculation with a Theileria sp. (sable)-infected tick stabilate. Consecutive measures of rectal temperature, lymph node size, white blood cell count (WBC), packed cell volume (PCV), hemoglobin concentration, differential leukocyte counts, leukocyte and erythrocyte morphology and percentage parasitemia were recorded. Data were compared with 15 age-matched PCR-negative control calves and nine older immune animals that had recovered from natural infection. Two non-pyrexic EI calves recovered uneventfully. Six pyrexic calves were treated, four of which died. Time to pyrexia and/or observation of schizonts and piroplasms was approximately two weeks. Total WBCs were unchanged post-infection (PI); neutrophils and typical monocytes decreased whereas typical lymphocytes (Ls) and atypical mononuclear leukocytes (AMLs), which were grouped together, increased. Parasitized and non-parasitized lymphocyte and AML (L/AML) size increased significantly PI. Piroplasms occurred intermittently at low frequencies («1 % of erythrocytes) after infection. Fatally infected calves were dehydrated, anemic, and icteric with hemorrhages and multi-organ infiltration by AMLs. The PCV and hemoglobin concentration increased PI, and platelet clumps were consistently observed. Experimental acute theileriosis in roan antelopes follows a similar pattern of disease progression to that in domestic livestock. Parasitized and non-parasitized AMLs are pivotal to the pathogenesis and require phenotypic characterization if we are to further our understanding of disease progression and severity in roan antelopes.

Exo-selective, Reductive Heck Derived Polynorbornenes with Enhanced Molecular Weights, Yields, and Hydrocarbon Gas Transport Properties.

Next-generation membranes use highly engineered polymeric structures with enhanced chain rigidity, yet difficulties in polymerization often limit molecular weights required for film formation. Addition-type polynorbornenes are promising materials for industrial gas separations, but suffer from these limitations owing to endo-exo monomeric mixtures that restrict polymerization sites. In this work, a synthetic approach employing the reductive Mizoroki-Heck reaction resulted in exo-selective products that polymerized up to >99% yields for ROMP and addition-type polymers, achieving molecular weights an order of magnitude higher than addition-type polymers from endo-exo mixtures and impressive side group stereoregularity. Due to this increased macromolecular control, these polynorbornenes demonstrate unique solubility-selective permeation with mixed gas selectivities that exceed commercially used PDMS. In addition to thermal and structural characterization, XRD and computational studies confirmed the results of pure and mixed-gas transport testing, which show highly rigid membranes with favorably disrupted chain packing.

Organotemplate-Free ß Zeolites: From Zeolite Synthesis to Hierarchical Structure Creation.

Interest in the production of ß zeolites in the absence of organic structure-directing agent (OSDA) has continued to grow consistently during the past decade. During this time, numerous strategies have been proposed to manipulate the hierarchy of zeolite pore structures in order to facilitate the transport of bulky reactants and to improve the accessibility of active sites in zeolite catalysts. In this work, we describe an organotemplate-free route to produce hierarchical ß zeolites. Using OSDA-free ß as the starting zeolites, we explored the applicability of various postsynthetic approaches to create hierarchical structures with mesoporosity, including framework stabilization, dealumination, conventional desilication, and hydrothermal desilication. While framework stabilization and dealumination were not effective in generating mesoporosity, they were necessary as modification steps to determine the efficacy of hierarchical structure creation. Compared to conventional desilication, hydrothermal desilication produces larger mesopores and much better preservation of microporosity and acidity because of the occurrence of recrystallization. The cost-effective, scalable production of organotemplate-free hierarchical ß zeolites could greatly enhance the adoption of ß zeolites in oil refining and petrochemical industries, where the advantages of hierarchically structured zeolites can dramatically improve catalytic performances in formulated catalysts.

Theileriosis (Cytauxzoonosis) in Roan antelope (Hippotragus equinus): field exposure to infection and identification of potential vectors.

Four hand-reared, naïve roan antelope, 4 months of age, were exposed to naturally infected pasture on a game farm in Mpumalanga Province, South Africa, where roan are known to die from theileriosis. Various clinical parameters were recorded during this period. The predominant ticks parasitising these animals at the time (January to February), were Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi adults. After a period of 5 weeks the animals developed signs of clinical theileriosis and were treated with buparvaquone to prevent mortality. Primary hyperplasia of the local draining lymph nodes (Lnn. anorectales) near the feeding site of adult R. evertsi evertsi indicated possible transmission of Theileria sp. (sable) by this tick species. After recovery from theileriosis, these animals were confirmed carriers of Theileria sp. (sable) by PCR (polymerase chain reaction) and DNA probe analysis. Laboratory-bred larvae and nymphs of R. evertsi evertsi and R. appendiculatus respectively, were fed on the ears of these roan antelope. Salivary glands from moulted and prefed adult ticks of each species were dissected and stained for Theileria spp., and the PCR and DNA probe applied to a representative batch of dissected glands. R. appendiculatus adults collected from grass in infected camps were also dissected after prefeeding them on rabbits. Salivary glands of both tick species showed infected acini on staining and were also positive for Theileria sp. (sable) only, on multiprotozoal PCR-screening analysis. There was no statistical significant difference between the infection rate and the intensity of infection between the two tick species. R. appendiculatus ticks collected from grass were also PCR-positive for Theileria sp. (sable).