ESTANCIAS DE INVESTIGACIÓN Y/O PRODUCCIÓN EN LA TITULACIÓN POR TESIS DEL BIÓLOGO MARINO DE LA UNIVERSIDAD AUTÓNOMA DE BAJA CALIFORNIA SUR

In higher education, completion efficiency can be measured considering the degree index determined by the completion rate and number of graduates in a cohort. The Marine Biologist study plan at Universidad Autónoma de Baja California Sur (UABCS) in Mexico, has been modified 11 times. One of the changes included the proposal of the subjects Research Stay and / or Production I and II starting from the 1996-I study plan, continuing up the current 2011-II plan, and adding III and IV, to direct the student toward research work production, which could turn out to be thesis writing. The objective of this work is to determine the possible relationship between Research Stay and / or Production II or III-IV and Marine Biology degree completion by thesis writing with the purpose of assessing completion time between cohorts that studied them with those previous to 1996. The work developed is longitudinal, quantitative and descriptive. The information obtained was provided by the Office of the Director of Student Services (Dirección de Servicios Escolares), SIIA (Portal de Sistema Integral de Información Administrativa), responsible persons of Research Stay and / or Production II or III-IV programs, and by printed and digital surveys applied to graduates who had completion by thesis writing with 1996-I and 2011-II study plans. The completion efficiency of Research Stay by thesis writing was analyzed using the mean of the time taken by the generations that did not carry out Research Stay and / or Production II or III-IV (Treatment 1) compared to the mean of the time taken by the generations that completed them (Stays II: Treatment 2; Stays III-IV: Treatment 3). A greater percentage of completion rate was observed in those that maintained the thesis topic developed in the Research Stay. These courses contribute to reduce completion time for graduates that choose thesis writing in higher research educations. The average time used by the students in thesis writing in T1 was 3.9 years, 2.4 for those in T2; and 1.2 for those in T3. For the other completion options offered by the University, 50% of Master's credits (Art 73 I) and Automatic Completion by 90 grade point average with no extraordinary exams (Art 73 III), were the ones that have had the most students with completion efficiency. Keywords: graduates – marine biologist – Mexico – role of a subject – terminal efficiencyEn la educación superior, la eficiencia terminal puede medirse considerando el índice de titulación determinándose por la proporción de titulados y el número de egresados de una cohorte. El plan de estudios de Biólogo Marino de la Universidad Autónoma de Baja California Sur (UABCS) en México, se ha modificado en 11 ocasiones, uno de los cambios incluyó la propuesta de las asignaturas Estancias de Investigación y/o Producción I y II a partir del plan 1996-I continuando hasta el plan vigente 2011-II, en el cual se incrementaron la III y IV, para dirigir al estudiante hacia la elaboración de un trabajo de investigación que podría convertirse en tesis. El objetivo de este trabajo fue determinar la posible relación entre las Estancias de Investigación y/o Producción II o III-IV y la titulación por tesis del Biólogo Marino con el fin de evaluar el tiempo de titulación entre las cohortes que las cursaron con las anteriores a 1996.  El trabajo desarrollado es de carácter longitudinal, cuantitativo y descriptivo. La información obtenida fue proporcionada por la Dirección de Servicios Escolares, el Portal de Sistema Integral de Información Administrativa (SIIA), las responsables de los programas de las Estancias de Investigación y/o Producción II ó III-IV y por encuestas impresas y digitales aplicadas a titulados por tesis de los planes de estudio 1996-I y 2011-II. Se analizó la efectividad de las Estancias en la titulación por tesis de los egresados utilizando las medias de los tiempos de las generaciones que no cursaron Estancias de Investigación y/o Producción II ó III-IV (Tratamiento 1) comparando con las medias de los tiempos de las generaciones que sí las cursaron (Estancias II: Tratamiento 2; Estancias III-IV: Tratamiento 3). Se observó mayor porcentaje de egresados en aquellos que mantienen el tema desarrollado en sus Estancias como tema de tesis. Estas asignaturas coadyuvan a reducir el tiempo de titulación de los egresados que optan por desarrollar tesis en instituciones de educación superior-investigación. El tiempo promedio utilizado por los tesistas del Tratamiento 1 fue de 3,9 años, los del tratamiento T2 fue de 2,4 años y los del Tratamiento T3 fue de 1,2 años. De las otras opciones de titulación que ofrece la Institución, el 50% de créditos de una Maestría (Art. 73 I) y Titulación Automática por Promedio de 90 sin exámenes extraordinarios (Art. 73 III), fueron las que más titulados han tenido. Palabras clave: asignatura – biólogo marino – eficiencia terminal – titulados –  Méxic

COMPARACIÓN DE LA BIODIVERSIDAD PARASITARIA DE PARALABRAX CLATHRATUS (GIRARD, 1854) Y P. HUMERALIS (VALENCIENNES, 1828) (PISCES: SERRANIDAE) DEL PACÍFICO ORIENTAL

Se presenta la biodiversidad parasitaria de Paralabrax clathratus (Girard, 1854) y P. humeralis (Valenciennes, 1828) (Pisces: Serranidae) del Pacífico Oriental, su especificidad hospedatoria y el papel que desempeñan en el ciclo de vida de los parásitos. La información es una compilación de los registros de diversos autores durante la revisión de los parásitos de los peces estudiados. Se encontró que la biodiversidad parasitaria de ambas especies de peces está agrupada en 22 familias (entre helmintos y crustáceos), dos órdenes y una clase. Paralabrax humeralis presenta mayor riqueza parasitaria que P. clathratus (n = 40 vs n = 27): monogeneos (n = 3 vs n = 3), digéneos (n = 10 vs n = 10), céstodos (n = 6 vs n = 1), acantocéfalos (n = 2 vs n = 1), nemátodos (n = 9 vs n = 4), copépodos (n = 8 vs n = 8), isópodos (n = 1 vs n = 0) e hirudineos (n = 1 vs n = 0). De esta riqueza parasitaria, se observó que los hospederos comparten diez familias: Diclidophoridae y Capsalidae (Monogenea), Opecoelidae y Hemiuridae (Digenea), Polymorphidae (Acantocephala), Anisakidae y Cucullanidae (Nematoda), Caligidae, Bomolochidae y Hatschekiidae (Copepoda). El índice de Sörensen cualitativo que sirvió para comparar la biodiversidad parasitaria a nivel de familia y de especie de P. clathratus y P. humeralis mostró un valor de 57,14% y de 11,94%, respectivamente. A pesar de esta diferencia, se observó una proporción similar de parásitos en los estadios larval y adulto, así como en los tipos de ciclos de vida y en el sitio de infección (ectoparásitos y endoparásitos) entre ambas especies de Paralabrax. Por otro lado, los parásitos que muestran cierta especificidad hospedatoria hacia serránidos son los copépodos de la familia Hatschekiidae y los céstodos del orden Trypanorhyncha que parasitan a peces elasmobranquios en estado adulto, el resto se consideran parásitos generalistas. Los céstodos, acantocéfalos y anisákidos registrados son formas larvarias indicando que utilizan a Paralabrax como hospederos intermediarios o paraténicos en sus ciclos de vida. Los monogéneos, digéneos y copépodos son formas adultas lo que sugiere que P. clathratus y P. humeralis son sus hospederos definitivos. Las diferencias observadas en la riqueza parasitaria de los hospederos pueden deberse a condiciones específicas del ambiente, de la presencia de diferentes hospederos intermediarios, del comportamiento alimentario y de su posible especificidad hospedatoria

PARASITOFAUNA DE PARANTHIAS COLONUS (VALENCIENNES, 1846) EN EL SARGENTO, BAJA CALIFORNIA SUR, MÉXICO

Paranthias colonus(Valenciennes, 1846) is used as fish bait replacing first class fish that have been overfished in the Gulf of California. Due to its recent commercial importance, the parasite fauna of P. colonusfrom of El Sargento, Baja California Sur, Mexico is characterized to define its role in the life cycle of its parasites. 30 fishes were fixed in 4% formaldehyde for later examination. Helminths and copepods were treated with conventional techniques specific to each kind of parasite. P. colonushad 100% prevalence and 46.5 mean intensity of parasites. Adults of Pseudorhabdosynochus sp., Prodistomum orientalis, Brachyphallus sp., Lecithochirium sp., Spinitectus sp., Caligus sp., Pandaridae, and Hatschekia sp. and larevae of Tetragonocephalidae, Scolex pleuronectis and Anisakis sp. were found. There was evidence of host specificity of Pseudorhabdosynochussp. and Hatschekiasp. by serranid fish. P. orientalisis reported for the second time. Hemiuridae are generalists so Paranthiashas added to this host range. The presence of the metacestodes S. pleuronectisand Tetragonocephalidae indicates their role in Paranthiasas intermediate or paratenic hosts because they are found in adult elasmobranches. Anisakissp. and Caligussp. are of wide geographic distribution and host range. Anisakissp. is the only worm that poses a potential danger to public health because it causes anisakidosis. Members of the family Pandaridae are almost exclusive parasites in elasmobranchians and Paranthiasis widely spread in its hosts. This work reports the first world record of hosts and localities of the studied materials.Paranthias colonus (Valenciennes, 1846) es un pez usado como carnada que ha sustituido a los peces de primera clase que se han sobreexplotado en el Golfo de California. Debido a su reciente importancia comercial en este trabajo se caracterizó la parasitofauna de P. colonusen la localidad de El Sargento, Baja California Sur, México, para definir el papel que tiene en el ciclo biológico de sus parásitos. Se adquirieron 30 ejemplares se fijaron en formaldehído al 4% para su posterior revisión. Los helmintos y copépodos se trataron con las técnicas convencionales propias de cada clase de parásito. Se tuvo un 100% de prevalencia y 46,5 de intensidad media de parasitismo general. Pseudorhabdosynochus sp., Prodistomum orientalis, Brachyphallus sp., Lecithochirium sp., Spinitectus sp., Caligus sp., Pandaridae y Hatschekia sp. son adultos y Tetragonocephalidae, Scolex pleuronectis y Anisakis sp. son formas larvarias. Se evidencia la especificidad hospedatoria de Pseudorhabdosynochus sp. y Hatschekia sp. por peces Serránidos. P. orientalisen el presente trabajo representa el segundo registro. Los hemiúridos son generalistas por lo que Paranthiasse agrega a este rango de hospederos. La presencia de metacéstodos de Tetragonocephalidae y S. pleuronectisen Paranthiasindica su papel como hospedero intermediario o paraténico, debido a que en etapa adulta se encuentran en elasmobranquios. Anisakis sp. y Caligus sp. son de amplia distribución geográfica y rango de hospederos. Anisakissp. es el único helminto que representa un peligro potencial para la salud pública por ser causante de Anisakidosis. Los miembros de la familia Pandaridae son parásitos casi exclusivos de elasmobranquios y Paranthiasdiversifica su rango hospedatorio. Finalmente, la parasitofauna del hospedero y localidad de este trabajo representan el primer registro a nivel mundial

Larvas de peces parasitadas por metacercarias de Hemiuridae y Fellodistomidae (Trematoda) en la laguna arrecifal de Puerto Morelos, Quintana Roo, México

Parasitized fish larvae collected with a neuston net (0.40 x 0.40 m mouth) at two sampling stations in the coral reef lagoon of Puerto Morelos, Quintana Roo, Mexico, from September to November 2002 were analyzed. Fish larvae and the parasites were stained together with acetic carmine and cleared with methyl salicilate. Parasites were removed from the host and mounted in permanent slides with synthetic resin. Unencysted metacercariae of Hemiuridae and Fellodistomidae were found in the stomach of Sphyraena barracuda (Sphyraenidae) (16), Serranidae (2) and Ctenogobius sp. (Gobiidae) (3); in the intestine of Gerres cinereus sp (Gerreidae) (2) and in the cloaca (12) and swim bladder (48) of Jenkinsia lamprotaenia (Clupeidae). Fish larvae are plankton feeders and as Acartia spinata and Paracalanus sp. are the most abundant copepods and the usual prey for predators, it is suggested that these microcrustaceans may be the first intermediate hosts and the usual infection via for fish larvae. Fish larvae would become the second or paratenic hosts and when adult fish feed on them, would become the final and definitive host.Se analizaron las muestras de larvas de peces recolectadas con una red de neuston (0.40 x 0.40 m de boca), en dos estaciones de muestreo en la laguna arrecifal de Puerto Morelos, Quintana Roo, de septiembre a noviembre de 2002, con el objetivo de identificar su fauna parasitaria. Las larvas de peces fueron teñidas junto con los parásitos con carmín acético, se transparentaron con salicilato de metilo y se extrajeron los parásitos, los cuales fueron montados en preparaciones permanentes. Se encontraron metacercarias de Hemiuridae y Fellodistomidae no enquistadas en el estómago de Sphyraena barracuda (Sphyraenidae) (16), en Serranidae (2) y Ctenogobius sp. (Gobiidae) (3); en el intestino de Gerres cinereus (Gerreidae)(2); en la cloaca (12) y vejiga natatoria (48) de Jenkinsia lamprotaenia (Clupeidae). Las larvas de peces son planctófagas y debido a que Acartia spinata y Paracalanus sp., son los copépodos más abundantes y las presas más comunes en el área de estudio, se considera que el modo de infección probable sea a través del consumo de estos microcrustáceos que actúan como primeros hospederos intermediarios. Las larvas de peces serían los segundos hospederos intermediarios u hospederos paraténicos y los peces adultos, al depredar sobre las larvas, se infectarían con los parásitos convirtiéndose en los hospederos definitivos

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

An embedding technique to determine ττ backgrounds in proton-proton collision data

An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

Peer reviewe

Bose-Einstein correlations of charged hadrons in proton-proton collisions at s\sqrt s = 13 TeV

Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at $\sqrt{s}$ = 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at $\sqrt{s}$ = 7 TeV, as well as with theoretical predictions.[graphic not available: see fulltext]Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at $\sqrt{s} =$ 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at $\sqrt{s} =$ 7 TeV, as well as with theoretical predictions

Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe

Search for dark matter in events with a leptoquark and missing transverse momentum in proton-proton collisions at 13 TeV

A search is presented for dark matter in proton-proton collisions at a center-of-mass energy of root s= 13 TeV using events with at least one high transverse momentum (p(T)) muon, at least one high-p(T) jet, and large missing transverse momentum. The data were collected with the CMS detector at the CERN LHC in 2016 and 2017, and correspond to an integrated luminosity of 77.4 fb(-1). In the examined scenario, a pair of scalar leptoquarks is assumed to be produced. One leptoquark decays to a muon and a jet while the other decays to dark matter and low-p(T) standard model particles. The signature for signal events would be significant missing transverse momentum from the dark matter in conjunction with a peak at the leptoquark mass in the invariant mass distribution of the highest p(T) muon and jet. The data are observed to be consistent with the background predicted by the standard model. For the first benchmark scenario considered, dark matter masses up to 500 GeV are excluded for leptoquark masses m(LQ) approximate to 1400 GeV, and up to 300 GeV for m(LQ) approximate to 1500 GeV. For the second benchmark scenario, dark matter masses up to 600 GeV are excluded for m(LQ) approximate to 1400 GeV. (C) 2019 The Author(s). Published by Elsevier B.V.Peer reviewe