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The rumen contains a great diversity of prokaryotic and eukaryotic microorganisms that allow the ruminant to utilize ligno-cellulose material and to convert non-protein nitrogen into microbial protein to obtain energy and amino acids. However, rumen fermentation also has potential deleterious consequences associated with the emissions of greenhouse gases, excessive nitrogen excreted in manure and may also adversely influence the nutritional value of ruminant products. While several strategies for optimizing the energy and nitrogen use by ruminants have been suggested, a better understanding of the key microorganisms involved and their activities is essential to manipulate rumen processes successfully. Diet is the most obvious factor influencing the rumen microbiome and fermentation. Among dietary interventions, the ban of antimicrobial growth promoters in animal production systems has led to an increasing interest in the use of plant extracts to manipulate the rumen. Plant extracts (e.g. saponins, polyphenol compounds, essential oils) have shown potential to decrease methane emissions and improve the efficiency of nitrogen utilization; however, there are limitations such as inconsistency, transient and adverse effects for their use as feed additives for ruminants. It has been proved that the host animal may also influence the rumen microbial population both as a heritable trait and through the effect of early-life nutrition on microbial population structure and function in adult ruminants. Recent developments have allowed phylogenetic information to be upscaled to metabolic information; however, research effort on cultivation of microorganisms for an in-depth study and characterization is needed. The introduction and integration of metagenomic, transcriptomic, proteomic and metabolomic techniques is offering the greatest potential of reaching a truly systems-level understanding of the rumen; studies have been focused on the prokaryotic population and a broader approach needs to be considered.

Jorge Ramos, an Emmy award-winning journalist, Univision's longtime anchorman and widely considered the \"voice of the voiceless\" within the Latino community, was forcefully removed from an Iowa press conference in 2015 by then-candidate Donald Trump after trying to ask about his plans on immigration. In this personal manifesto, Ramos sets out to examine what it means to be a Latino immigrant, or just an immigrant, in present-day America. Using current research and statistics, with a journalist's nose for a story, and interweaving his own personal experience, Ramos shows us the changing face of America while also trying to find an explanation for why he, and millions of others, still feel like strangers in this country.

In this study we report, the synthesis of ZnO and its doping with Transition Metal Oxides -TMO-, such as Cr 2 O 3 , MnO 2 , FeO, CoO, NiO, Cu 2 O and CuO. Various characterization techniques were employed to investigate the structural properties. The X-ray diffraction (XRD) data and Rietveld refinement confirmed the presence of TMO phases and that the ZnO structure was not affected by the doping with TMO which was corroborated using transmission Electron microscopy (TEM). Surface areas were low due to blockage of adsorption sites by particle aggregation. TMO doping concentration in the range of 3.7–5.1% was important to calculate the catalytic activity. The UV–Visible spectra showed the variation in the band gap of TMO/ZnO ranging from 3.45 to 2.46 eV. The surface catalyzed decomposition of H 2 O 2 was used as the model reaction to examine the photocatalytic activity following the oxygen production and the systems were compared to bulk ZnO and commercial TiO 2 -degussa (Aeroxyde-P25). The results indicate that the introduction of TMO species increase significantly the photocatalytic activity. The sunlight photocatalytic performance in ZnO-doped was greater than bulk-ZnO and in the case of MnO 2 , CoO, Cu 2 O and CuO surpasses TiO 2 (P25-Degussa). This report opens up a new pathway to the design of high-performance materials used in photocatalytic degradation under visible light irradiation.

The Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), is the primary vector of Candidatus Liberibacter asiaticus (Las) implicated as causative agent of citrus huanglongbing (citrus greening), currently the most serious citrus disease worldwide. Las is transmitted by D. citri in a persistent-circulative manner, but the question of replication of this bacterium in its psyllid vector has not been resolved. Thus, we studied the effects of the acquisition access period (AAP) by nymphs and adults of D. citri on Las acquisition, multiplication and inoculation/transmission. D. citri nymphs or adults (previously non-exposed to Las) were caged on Las-infected citrus plants for an AAP of 1, 7 or 14 days. These 'Las-exposed' psyllids were then transferred weekly to healthy citrus or orange jasmine plants, and sampled via quantitative polymerase chain reaction (qPCR) analysis 1-42 days post-first access to diseased plants (padp); all tested nymphs became adults 7-14 days padp. Our results indicate that following 1 or 7 day AAP as nymphs 49-59% of Las-exposed psyllids became Las-infected (qPCR-positive), whereas only 8-29% of the psyllids were infected following 1-14 day AAP as adults. Q-PCR analysis also indicated that Las titer in the Las-exposed psyllids (relative to that of the psyllid S20 ribosomal protein gene) was: 1) significantly higher, and increasing at a faster rate, following Las acquisition as nymphs compared to that following Las acquisition as adults; 2) higher as post-acquisition time of psyllids on healthy plants increased reaching a peak at 14-28 days padp for nymphs and 21-35 days padp for adults, with Las titer decreasing or fluctuating after that; 3) higher with longer AAP on infected plants, especially with acquisition as adults. Our results strongly suggest that Las multiplies in both nymphs and adults of D. citri but attains much higher levels in a shorter period of time post-acquisition when acquired by nymphs than when acquired by adults, and that adults may require longer access to infected plants compared to nymphs for Las to reach higher levels in the vector. However, under the conditions of our experiments, only D. citri that had access to infected plants as nymphs were able to inoculate Las into healthy citrus seedlings or excised leaves. The higher probability of Las inoculation into citrus by psyllids when they have acquired this bacterium from infected plants during the nymphal rather than the adult stage, as reported by us and others, has significant implications in the epidemiology and control of this economically important citrus disease.

Clonal diversity is a consequence of cancer cell evolution driven by Darwinian selection. Precise characterization of clonal architecture is essential to understand the evolutionary history of tumor development and its association with treatment resistance. Here, using a single-cell DNA sequencing, we report the clonal architecture and mutational histories of 123 acute myeloid leukemia (AML) patients. The single-cell data reveals cell-level mutation co-occurrence and enables reconstruction of mutational histories characterized by linear and branching patterns of clonal evolution, with the latter including convergent evolution. Through xenotransplantion, we show leukemia initiating capabilities of individual subclones evolving in parallel. Also, by simultaneous single-cell DNA and cell surface protein analysis, we illustrate both genetic and phenotypic evolution in AML. Lastly, single-cell analysis of longitudinal samples reveals underlying evolutionary process of therapeutic resistance. Together, these data unravel clonal diversity and evolution patterns of AML, and highlight their clinical relevance in the era of precision medicine. Understanding the evolutionary trajectory of cancer samples may enable understanding resistance to treatment. Here, the authors used single cell sequencing of a cohort of acute myeloid leukemia tumours and identify features of linear and branching evolution in tumours.

Tikal has long been viewed as one of the leading polities of the ancient Maya realm, yet how the city was able to maintain its substantial population in the midst of a tropical forest environment has been a topic of unresolved debate among researchers for decades. We present ecological, paleoethnobotanical, hydraulic, remote sensing, edaphic, and isotopic evidence that reveals how the Late Classic Maya at Tikal practiced intensive forms of agriculture (including irrigation, terrace construction, arboriculture, household gardens, and short fallow swidden) coupled with carefully controlled agroforestry and a complex system of water retention and redistribution. Empirical evidence is presented to demonstrate that this assiduously managed anthropogenic ecosystem of the Classic period Maya was a landscape optimized in a way that provided sustenance to a relatively large population in a preindustrial, low-density urban community. This landscape productivity optimization, however, came with a heavy cost of reduced environmental resiliency and a complete reliance on consistent annual rainfall. Recent speleothem data collected from regional caves showed that persistent episodes of unusually low rainfall were prevalent in the mid-9th century A.D., a time period that coincides strikingly with the abandonment of Tikal and the erection of its last dated monument in A.D. 869. The intensified resource management strategy used at Tikal—already operating at the landscape’s carrying capacity—ceased to provide adequate food, fuel, and drinking water for the Late Classic populace in the face of extended periods of drought. As a result, social disorder and abandonment ensued. Significance The rise of complex societies and sustainable land use associated with urban centers has been a major focus for anthropologists, geographers, and ecologists. Here we present a quantitative assessment of the agricultural, agroforestry, and water management strategies of the inhabitants of the prominent ancient Maya city of Tikal, and how their land use practices effectively sustained a low-density urban population for many centuries. Our findings also reveal, however, that the productive landscape surrounding Tikal, managed to the brink of its carrying capacity during the Late Classic period, did not have the resilience to withstand the droughts of the 9th century. These results offer essential insights that address the question of why some cities thrive while others decline.

The capability to grow microalgae in nonsterilized wastewater is essential for an application of this technology in an actual industrial process. Batch experiments were carried out with the species in nonsterilized urban wastewater from local treatment plants to measure both the algal growth and the nutrient consumption. Chlorella protothecoides showed a high specific growth rate (about 1 day⁻¹), and no effects of bacterial contamination were observed. Then, this microalgae was grown in a continuous photobioreactor with CO₂–air aeration in order to verify the feasibility of an integrated process of the removal of nutrient from real wastewaters. Different residence times were tested, and biomass productivity and nutrients removal were measured. A maximum of microalgae productivity was found at around 0.8 day of residence time in agreement with theoretical expectation in the case of light-limited cultures. In addition, N-NH₄ and P-PO₄ removal rates were determined in order to model the kinetic of nutrients uptake. Results from batch and continuous experiments were used to propose an integrated process scheme of wastewater treatment at industrial scale including a section with C. protothecoides.