856 research outputs found
Curvas de crecimiento predestete en terneros del sistema de doble propósito.
Existen pocos estudios sobre curvas de crecimiento predestete en bovinos de doble propósito (DP), generalmente éstos son cruces de Bos taurus x Bos indicus. La curva de crecimiento debe señalar los puntos críticos en esta etapa de cría para aplicar los correctivos necesarios, básicamente en aspectos de manejo y alimentación, su importancia se da en términos técnico-económicos. El trabajo se realizó en el Centro de Investigación El Nus del ICA, ubicado en zona de ladera y clima medio de Antioquia. Los pesos mensuales, obtenidos desde 1986 hasta 1992 de 479 terneros criados bajo el sistema de DP, se examinaron mediante análisis de regresión y correlación para 48 animales, según sexo y grupo genético. El peso promedio al nacimiento fue de 31.14 más o menos 4.82, y al destete, de 149.84 más o menos 36.91. En estas fechas los machos superaron a las hembras en 0.95 y 13.40 kg, respectivamente. Se determinaron curvas de crecimiento desde el nacimiento hasta el destete (9 meses) para cada una de las composiciones genéticas, encontrándose r al cuadrado superiores al 69 por ciento para las ecuaciones lineal, cuadrática y cúbica. La ecuación lineal (Y igual 31.980 más 0.411x con r al cuadrado igual 0.720) fue la más utilizada por su fácil manejo y baja variabilida
Cruces de ganado de doble propósito en la zona montañosa baja colombiana, 3. Producción de leche y carne.
No obstante que en Colombia se han usado híbridos Bos taurus-Bos indicus como ganado de doble propósito, no se ha hecho una comparación experimental entre los diferentes cruces que se pueden hacer con las razas existentes en el país. El objetivo del trabajo fue el estudiar el comportamiento en producción de leche y carne de 2 razas puras, 4 F sub 1, un F sub 2 y 2 trihíbridos. Las vacas permanecieron en pastoreo y se ordeñaron una vez al día. Los terneros estuvieron con sus madres durante 8 horas y fueron destetados a los 9 meses. Los datos se analizaron por el método de cuadrados mínimos. Los análisis de varianza mostraron efecto significativo (P menor que 0.01) de grupo racial sobre la longitud de la lactancia, producción por lactancia, producción de leche diaria y producción de carne al destete. El promedio de la longitud de lactancia del Cebú fue de 155.5 días, cifra que fue superada en 69.9 por ciento por el promedio de los 4 media sangre F sub 1 (Holstein Rojo x Cebú, Pardo Suizo x Cebú, Normando x Cebú y Blanco Orejinegro x Cebú). El Cebú tuvo un promedio de producción por lactancia de 451.8 kg y los 4 media media sangres F sub 1, lo aventajaron en 110.9 por ciento. La heterosis desarrollada en producción por lactancia por el F sub 1 Blanco Orejinegro x Cebú sobre el promedio de las 2 razas de los padres fue de 50.3 por ciento. La pérdida de vigor híbrido del F sub 2 Holstein Negro x Cebú en relación con el F sub 1 Holstein Rojo x Cebú fue de 38.9 por ciento. La producción diaria varió entre 2.400 kg (Blanco Orejinegro) y 4.114 kg (Holstein Rojo x Cebú). La producción de carne del Cebú (peso al destete de la cría) fue de 156.5 kg, superando al promedio de los 4 media sangres en 16.3 por ciento. Otro grupo destacado en producción de carne al destete fue el tri-híbrido Cebú (Holstein Negro x Blanco Orejinegro) con 148.5 kgGanado de doble propósito-Ganaderia doble proposit
Lithium and Halpha in stars and brown dwarfs of sigma Orionis
We present intermediate- and low-resolution optical spectra around Halpha and
LiI 6708 A for a sample of 25 low mass stars and 2 brown dwarfs with confirmed
membership in the pre-main sequence stellar sigma Orionis cluster. Our
observations are intended to investigate the age of the cluster. The spectral
types derived for our target sample are found to be in the range K6-M8.5, which
corresponds to a mass interval of roughly 1.2-0.02 Msun on the basis of
state-of-the-art evolutionary models. Radial velocities (except for one object)
are found to be consistent with membership in the Orion complex. All cluster
members show considerable Halpha emission and LiI in absorption, which is
typical of very young ages. We find that our pseudo-equivalent widths appear
rather dispersed (and intense in the case of Halpha) for objects cooler than
M3.5 spectral class, occurring at the approximate mass where low mass stars are
expected to become fully convective. The least massive brown dwarf in our
sample, SOri 45 (M8.5, ~0.02 Msun), displays variable Halpha emission and a
radial velocity that differs from the cluster mean velocity. Tentative
detection of forbidden lines in emission indicates that this brown dwarf may be
accreting mass from a surrounding disk. We also present recent computations of
LiI curves of growth for low gravities and for the temperature interval (about
4000-2600 K) of our sample. The comparison of our observations to these
computations allows us to infer that no lithium depletion has yet taken place
in sigma Orionis, and that the observed pseudo-equivalent widths are consistent
with a cluster initial lithium abundance close to the cosmic value. Hence, the
upper limit to the sigma Orionis cluster age can be set at 8 Myr, with a most
likely value around 2-4 Myr.Comment: 17 pages (figures included). Accepted for publication in A&
Evidence of beta amyloid independent small vessel disease in familial Alzheimer\u27s disease
\ua9 2022 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology. We studied small vessel disease (SVD) pathology in Familial Alzheimer\u27s disease (FAD) subjects carrying the presenilin 1 (PSEN1) p.Glu280Ala mutation in comparison to those with sporadic Alzheimer\u27s disease (SAD) as a positive control for Alzheimer\u27s pathology and Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) bearing different NOTCH3 mutations, as positive controls for SVD pathology. Upon magnetic resonance imaging (MRI) in life, some FAD showed mild white matter hyperintensities and no further radiologic evidence of SVD. In post-mortem studies, total SVD pathology in cortical areas and basal ganglia was similar in PSEN1 FAD and CADASIL subjects, except for the feature of arteriosclerosis which was higher in CADASIL subjects than in PSEN1 FAD subjects. Further only a few SAD subjects showed a similar degree of SVD pathology as observed in CADASIL. Furthermore, we found significantly enlarged perivascular spaces in vessels devoid of cerebral amyloid angiopathy in FAD compared with SAD and CADASIL subjects. As expected, there was greater fibrinogen-positive perivascular reactivity in CADASIL but similar reactivity in PSEN1 FAD and SAD groups. Fibrinogen immunoreactivity correlated with onset age in the PSEN1 FAD cases, suggesting increased vascular permeability may contribute to cognitive decline. Additionally, we found reduced perivascular expression of PDGFRβ AQP4 in microvessels with enlarged PVS in PSEN1 FAD cases. We demonstrate that there is Aβ-independent SVD pathology in PSEN1 FAD, that was marginally lower than that in CADASIL subjects although not evident by MRI. These observations suggest presence of covert SVD even in PSEN1, contributing to disease progression. As is the case in SAD, these consequences may be preventable by early recognition and actively controlling vascular disease risk, even in familial forms of dementia
Simulation of the CMS Resistive Plate Chambers
The Resistive Plate Chamber (RPC) muon subsystem contributes significantly to
the formation of the trigger decision and reconstruction of the muon trajectory
parameters. Simulation of the RPC response is a crucial part of the entire CMS
Monte Carlo software and directly influences the final physical results. An
algorithm based on the parametrization of RPC efficiency, noise, cluster size
and timing for every strip has been developed. Experimental data obtained from
cosmic and proton-proton collisions at TeV have been used for
determination of the parameters. A dedicated validation procedure has been
developed. A good agreement between the simulated and experimental data has
been achieved.Comment: to be published in JINS
Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the Consortium of Investigators of Modifiers of BRCA1/BRCA2 (CIMBA)
Background: In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers. Methods: We have genotyped rs744154 in 9408 BRCA1 and 5632 BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and assessed its association with breast cancer risk using a retrospective weighted cohort approach. Results: We found no evidence of association with breast cancer risk for BRCA1 (per-allele HR: 0.98, 95% CI: 0.93–1.04, P=0.5) or BRCA2 (per-allele HR: 0.97, 95% CI: 0.89–1.06, P=0.5) mutation carriers. Conclusion: This SNP is not a significant modifier of breast cancer risk for mutation carriers, though weak associations cannot be ruled out. A Osorio1, R L Milne2, G Pita3, P Peterlongo4,5, T Heikkinen6, J Simard7, G Chenevix-Trench8, A B Spurdle8, J Beesley8, X Chen8, S Healey8, KConFab9, S L Neuhausen10, Y C Ding10, F J Couch11,12, X Wang11, N Lindor13, S Manoukian4, M Barile14, A Viel15, L Tizzoni5,16, C I Szabo17, L Foretova18, M Zikan19, K Claes20, M H Greene21, P Mai21, G Rennert22, F Lejbkowicz22, O Barnett-Griness22, I L Andrulis23,24, H Ozcelik24, N Weerasooriya23, OCGN23, A-M Gerdes25, M Thomassen25, D G Cruger26, M A Caligo27, E Friedman28,29, B Kaufman28,29, Y Laitman28, S Cohen28, T Kontorovich28, R Gershoni-Baruch30, E Dagan31,32, H Jernström33, M S Askmalm34, B Arver35, B Malmer36, SWE-BRCA37, S M Domchek38, K L Nathanson38, J Brunet39, T Ramón y Cajal40, D Yannoukakos41, U Hamann42, HEBON37, F B L Hogervorst43, S Verhoef43, EB Gómez García44,45, J T Wijnen46,47, A van den Ouweland48, EMBRACE37, D F Easton49, S Peock49, M Cook49, C T Oliver49, D Frost49, C Luccarini50, D G Evans51, F Lalloo51, R Eeles52, G Pichert53, J Cook54, S Hodgson55, P J Morrison56, F Douglas57, A K Godwin58, GEMO59,60,61, O M Sinilnikova59,60, L Barjhoux59,60, D Stoppa-Lyonnet61, V Moncoutier61, S Giraud59, C Cassini62,63, L Olivier-Faivre62,63, F Révillion64, J-P Peyrat64, D Muller65, J-P Fricker65, H T Lynch66, E M John67, S Buys68, M Daly69, J L Hopper70, M B Terry71, A Miron72, Y Yassin72, D Goldgar73, Breast Cancer Family Registry37, C F Singer74, D Gschwantler-Kaulich74, G Pfeiler74, A-C Spiess74, Thomas v O Hansen75, O T Johannsson76, T Kirchhoff77, K Offit77, K Kosarin77, M Piedmonte78, G C Rodriguez79, K Wakeley80, J F Boggess81, J Basil82, P E Schwartz83, S V Blank84, A E Toland85, M Montagna86, C Casella87, E N Imyanitov88, A Allavena89, R K Schmutzler90, B Versmold90, C Engel91, A Meindl92, N Ditsch93, N Arnold94, D Niederacher95, H Deißler96, B Fiebig97, R Varon-Mateeva98, D Schaefer99, U G Froster100, T Caldes101, M de la Hoya101, L McGuffog49, A C Antoniou49, H Nevanlinna6, P Radice4,5 and J Benítez1,3 on behalf of CIMB
Monitoring an Alien Invasion: DNA Barcoding and the Identification of Lionfish and Their Prey on Coral Reefs of the Mexican Caribbean
BACKGROUND: In the Mexican Caribbean, the exotic lionfish Pterois volitans has become a species of great concern because of their predatory habits and rapid expansion onto the Mesoamerican coral reef, the second largest continuous reef system in the world. This is the first report of DNA identification of stomach contents of lionfish using the barcode of life reference database (BOLD). METHODOLOGY/PRINCIPAL FINDINGS: We confirm with barcoding that only Pterois volitans is apparently present in the Mexican Caribbean. We analyzed the stomach contents of 157 specimens of P. volitans from various locations in the region. Based on DNA matches in the Barcode of Life Database (BOLD) and GenBank, we identified fishes from five orders, 14 families, 22 genera and 34 species in the stomach contents. The families with the most species represented were Gobiidae and Apogonidae. Some prey taxa are commercially important species. Seven species were new records for the Mexican Caribbean: Apogon mosavi, Coryphopterus venezuelae, C. thrix, C. tortugae, Lythrypnus minimus, Starksia langi and S. ocellata. DNA matches, as well as the presence of intact lionfish in the stomach contents, indicate some degree of cannibalism, a behavior confirmed in this species by the first time. We obtained 45 distinct crustacean prey sequences, from which only 20 taxa could be identified from the BOLD and GenBank databases. The matches were primarily to Decapoda but only a single taxon could be identified to the species level, Euphausia americana. CONCLUSIONS/SIGNIFICANCE: This technique proved to be an efficient and useful method, especially since prey species could be identified from partially-digested remains. The primary limitation is the lack of comprehensive coverage of potential prey species in the region in the BOLD and GenBank databases, especially among invertebrates
DNA strand break repair and neurodegeneration.
A number of DNA repair disorders are known to cause neurological problems. These disorders can be broadly characterised into early developmental, mid-to-late developmental or progressive. The exact developmental processes that are affected can influence disease pathology, with symptoms ranging from early embryonic lethality to late-onset ataxia. The category these diseases belong to depends on the frequency of lesions arising in the brain, the role of the defective repair pathway, and the nature of the mutation within the patient. Using observations from patients and transgenic mice, we discuss the importance of double strand break repair during neuroprogenitor proliferation and brain development and the repair of single stranded lesions in neuronal function and maintenance
Efficacy and safety of preoperative preparation with Lugol''s iodine solution in euthyroid patients with Graves’ disease (LIGRADIS Trial): Study protocol for a multicenter randomized trial
Background: Currently, both the American Thyroid Association and the European Thyroid Association recommend preoperative preparation with Lugol''s Solution (LS) for patients undergoing thyroidectomy for Graves’ Disease (GD), but their recommendations are based on low-quality evidence. The LIGRADIS trial aims to provide evidence either to support or refute the systematic use of LS in euthyroid patients undergoing thyroidectomy for GD. Methods: A multicenter randomized controlled trial will be performed. Patients =18 years of age, diagnosed with GD, treated with antithyroid drugs, euthyroid and proposed for total thyroidectomy will be eligible for inclusion. Exclusion criteria will be prior thyroid or parathyroid surgery, hyperparathyroidism that requires associated parathyroidectomy, thyroid cancer that requires adding a lymph node dissection, iodine allergy, consumption of lithium or amiodarone, medically unfit patients (ASA-IV), breastfeeding women, preoperative vocal cord palsy and planned endoscopic, video-assisted or remote access surgery. Between January 2020 and January 2022, 270 patients will be randomized for either receiving or not preoperative preparation with LS. Researchers will be blinded to treatment assignment. The primary outcome will be the rate of postoperative complications: hypoparathyroidism, recurrent laryngeal nerve injury, hematoma, surgical site infection or death. Secondary outcomes will be intraoperative events (Thyroidectomy Difficulty Scale score, blood loss, recurrent laryngeal nerve neuromonitoring signal loss), operative time, postoperative length of stay, hospital readmissions, permanent complications and adverse events associated to LS. Conclusions: There is no conclusive evidence supporting the benefits of preoperative treatment with LS in this setting. This trial aims to provide new insights into future Clinical Practice Guidelines recommendations. Trial registration: ClinicalTrials.gov identifier: NCT03980132. © 202
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