The effect of parasites on host behaviour is generally considered an example of the extended phenotype, implying that parasite genes alter host behaviour to benefit the parasite. While the extended ...phenotype is a valid perspective supported by empirical examples, this approach was proposed from an evolutionary perspective and it does not fully explain all processes that occur at ecological time scales. For instance, the roles of the ontogenetic environment, memory and learning in forming the host phenotype are not explicitly mentioned. Furthermore, the cumulative effect of diverse populations or communities of parasites on host phenotype cannot be attributed to a particular genotype, much less to a particular gene. Building on the idea that the behaviour of a host is the result of a complex process, which certainly goes beyond a specific parasite gene, we use Niche Construction Theory to describe certain systems that are not generally the main focus in the extended phenotype model. We introduce three niche construction models with corresponding empirical examples that capture the diversity and complexity of host-parasite interactions, providing predictions that simpler models cannot generate. We hope that this novel perspective will inspire further research on the topic, given the impact of ecological factors on both short-, and long-term effects of parasitism.
•Parasites can induce behavioural changes in hosts.•Extended phenotype theory has been suggested to explain this phenomenon.•Niche construction theory improves the interpretation of host manipulation.•We propose new models based on empirical examples to show the complexity of this process.
The chemical compounds carrying the thiol group (-SH) have been considered essential in recent prebiotic studies regarding the polymerization of amino acids. We have searched for this kind of ...compounds toward the Galactic Centre quiescent cloud G+0.693-0.027. We report the first detection in the interstellar space of the trans-isomer of monothioformic acid (t-HC(O)SH) with an abundance of ~ 1 × 10
−10
. Additionally, we provide a solid confirmation of the gauche isomer of ethyl mercaptan (g-C
2
H
5
SH) with an abundance of ~ 3 × 10
−10
, and we also detect methyl mercaptan (CH
3
SH) with an abundance of ~ 5 × 10
−9
. Abundance ratios were calculated for the three SH-bearing species and their OH-analogues, revealing similar trends between alcohols and thiols with increasing complexity. Possible chemical routes for the interstellar synthesis of t-HC(O)SH, CH
3
SH and C
2
H
5
SH are discussed, as well as the relevance of these compounds in the synthesis of prebiotic proteins in the primitive Earth.
Multidrug resistant (MDR) microorganisms represent a threat for patients admitted in Intensive Care Units (ICUs). The objective of the present study is to analyse the results of epidemiological ...surveillance cultures for these microorganisms in one of these units.
General ICU. Retrospective analysis, descriptive statistics. Analysis of epidemiological surveillance cultures for MDR microorganisms in 2015. Studied microorganisms: Methicillin-resistant Staphylococcus aureus (MRSA), ESBL-and/or carbapenemase-producing Klebsiella pneumoniae (CESBL-KP) and MDR Acinetobacter baumannii (MDRAB).
One thousand, two hundred and fifty nine patients admitted. A total of 2,234 specimens from 384 patients were analysed (690, 634, 62 and 286 were rectal, throat, nasal and skin swabs respectively). Global APACHE II was 18.3 ± 8 versus 21.7 ± 7.8 in patients colonized/infected on admission. Global mortality was 19.7% versus 22.3% in patients colonized/infected on admission. The higher sensitivities achieved with the different samples for the different microorganism detection were as follows. MRSA: 79% and 90% for nasal and nasal + throat swabs, respectively. MDRAB: 80% and 95% for throat and throat + rectal swabs, respectively. CESBL-KP: 95% and 98% for rectal and rectal + throat swabs, respectively. 94 out of the 384 patients (24.4%) were colonized/infected with MDR at admission. 134 patients (10.6% of the total patients admitted) were colonized/infected with a total of 169 MMR during the hospital stay. MRSA has the earliest colonization/infection (9.2 ± 6.4days) and ESBL-producing Enterobacteriaceae, the latest (18.7± 16.4 days).
24.4% of patients were colonized/infected by MDR at admission. Nasal, throat and rectal swabs were the most effective specimens for recovering MRSA, MDRAB and CESBL-KP, respectively. The combination of two specimens improves MDR detection except for CESBL-KP. Skin swabs are worthless. The most prevalent MDR at admission were ESBL-producing Enterobacteriaceae while the most frequent hospital acquired MDR was MDRAB..
Both photoelectron spectroscopy (PES) data and PhotoElectron-PhotoIon-Coincidence (PEPICO) spectra obtained from a synchrotron facility have been used to examine the electronic structure and the ...dissociative ionization of halomethyl thiocyantes in the valence and shallow-core S 2p and Cl 2p regions. Two simple and closely related molecules, namely, CCl
SCN and CCl
FSCN, have been analyzed to assess the role of halogen substitution in the electronic properties of thiocyanates. The assignment of the He(I) photoelectron spectra has been achieved with the help of quantum chemical calculations at the outer-valence Green's function (OVGF) level of approximation. The first ionization energies observed at 10.55 and 10.78 eV for CCl
SCN and CCl
FSCN, respectively, are assigned to ionization processes from the sulfur lone pair orbital n(S). When these molecules are compared with CX
SCN (X = H, Cl, F) species, a linear relationship between the vertical first ionization energy and electronegativity of CX
group is observed. Irradiation of CCl
SCN and CCl
FSCN with photons in the valence energy regions leads to the formation of CCl
X
and CClXSCN
ions (X = Cl or F). Additionally, the achievement of the fragmentation patterns and the total ion yield spectra obtained from the PEPICO data in the S 2p and Cl 2p regions and several dissociation channels can be inferred for the core-excited species by using the triple coincidence PEPIPICO (PhotoElectron-PhotoIon-PhotoIon-Coincidence) spectra.
The TOTEM experiment at the CERN LHC has measured elastic proton–proton scattering at the centre-of-mass energy
s
=
8
TeV and four-momentum transfers squared, |
t
|, from
6
×
10
-
4
to 0.2 GeV
2
. ...Near the lower end of the
t
-interval the differential cross-section is sensitive to the interference between the hadronic and the electromagnetic scattering amplitudes. This article presents the elastic cross-section measurement and the constraints it imposes on the functional forms of the modulus and phase of the hadronic elastic amplitude. The data exclude the traditional Simplified West and Yennie interference formula that requires a constant phase and a purely exponential modulus of the hadronic amplitude. For parametrisations of the hadronic modulus with second- or third-order polynomials in the exponent, the data are compatible with hadronic phase functions giving either central or peripheral behaviour in the impact parameter picture of elastic scattering. In both cases, the
ρ
-parameter is found to be
0.12
±
0.03
. The results for the total hadronic cross-section are
σ
tot
=
(
102.9
±
2.3
)
mb and
(
103.0
±
2.3
)
mb for central and peripheral phase formulations, respectively. Both are consistent with previous TOTEM measurements.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The TOTEM collaboration has measured the proton-proton total cross section at √s=8 TeV using a luminosity-independent method. In LHC fills with dedicated beam optics, the Roman pots have been ...inserted very close to the beam allowing the detection of ~90% of the nuclear elastic scattering events. Simultaneously the inelastic scattering rate has been measured by the T1 and T2 telescopes. By applying the optical theorem, the total proton-proton cross section of (101.7±2.9) mb has been determined, well in agreement with the extrapolation from lower energies. This method also allows one to derive the luminosity-independent elastic and inelastic cross sections: σ(el)=(27.1±1.4) mb; σ(inel)=(74.7±1.7) mb.
Gas and crystal structures of CCl2FSCN Martínez, Yanina Berrueta; Rodríguez Pirani, Lucas S.; Erben, Mauricio F. ...
Journal of molecular structure,
03/2017, Letnik:
1132
Journal Article
Recenzirano
Odprti dostop
Dichlorofluoromethyl thiocyanate, CCl2FSCN, was structurally studied in the solid and in the gas phase by means of single-crystal X-ray (XRD) and gas electron diffraction (GED), respectively. In the ...gas phase the title molecule adopts two stable conformers, described by the FC–SC dihedral angle. The gauche-conformer (FC bond with respect to the SC bond) is more stable than the anti-conformer. In this work we present the first experimental evidence for the existence of the anti-CF2ClSCN form. In the solid state only the most stable gauche-conformer was found. Intermolecular interactions were detected in the crystal structure and analyzed. A structural comparison of the results with those of related species as CCl2FSCN, CCl3SCN and CH2ClSCN is presented.
Display omitted
•The structure of CCl2FSCN is studied in both crystal and gas phases.•The anti conformation of CCl2FSCN has been determined in the gas phase.•In the crystal different intermolecular interactions were identified and analyzed.
The observation time in mild traumatic brain injury (mTBI) is controversial. Our aim was to assess the risk of neurological complications in mTBI with and without antithrombotic treatment.
We ...retrospectively evaluated patients with mTBI seen in the emergency room for 3 years. We considered MTBI those with Glasgow ≥13 at admission. A cranial CT was performed in all cases with ≥1 risk factor at admission and at 24 h in those with neurological impairment or initial pathological cranial CT. Complications in the following 3 months were retrospectively reviewed.
We evaluated 907 patients with a mean age of 73 ± 19 years. Ninety-one percent presented risk factors, with 60% on antithrombotic treatment. We detected 11% of initial brain hemorrhage, 0.4% at 24 h, and no cases at 3 months. Antithrombotic treatment was not associated with an increased risk of brain hemorrhage (9.9% with vs 11.9% without treatment, p = 0.3). 39% of the hemorrhages presented neurological symptoms (18% post-traumatic amnesia, 12% headache, 8% vomiting, 1% seizures), with 78.4% having mild symptoms. Of the 4 hemorrhages detected at 24 h, 3 were asymptomatic and one case that worsened the initial headache. No asymptomatic patient without lesion on initial clinical cranial CT presented at 24 h.
Our study suggests that patients with asymptomatic mTBI, without a lesion on the initial cranial CT, would not require the observation period or CT control regardless of antithrombotic treatment or INR level.
Context.
Theories of the origins of life propose that early cell membranes were synthesised from amphiphilic molecules simpler than phospholipids, such as fatty alcohols. The discovery in the ...interstellar medium (ISM) of ethanolamine, the simplest phospholipid head group, raises the question whether simple amphiphilic molecules are also synthesised in space.
Aims.
We investigate whether precursors of fatty alcohols are present in the ISM.
Methods.
To do this, we have carried out a spectral survey at 7, 3, 2 and 1 mm towards the Giant Molecular Cloud G+0.693-0.027 located in the Galactic centre using the IRAM 30 m and Yebes 40 m telescopes.
Results.
Here, we report the detection in the ISM of the primary alcohol
n
-propanol (in both conformers
Ga
-
n
-C
3
H
7
OH and
Aa
-
n
-C
3
H
7
OH), a precursor of fatty alcohols. The derived column densities of
n
-propanol are (5.5 ± 0.4) × 10
13
cm
−2
for the
Ga
conformer and (3.4 ± 0.3) × 10
13
cm
−2
for the
Aa
conformer, which imply molecular abundances of (4.1 ± 0.3) × 10
−10
for
Ga
-
n
-C
3
H
7
OH and of (2.5 ± 0.2) × 10
−10
for
Aa
-
n
-C
3
H
7
OH. We also searched for the
AGa
conformer of
n
-butanol
AGa
-
n
-C
4
H
9
OH without success, yielding an upper limit to its abundance of ≤4.1 × 10
−11
. The inferred CH
3
OH:C
2
H
5
OH:C
3
H
7
OH:C
4
H
9
OH abundance ratios are 1:0.04:0.006:≤0.0004 towards G+0.693-0.027, that is, they decrease roughly by one order of magnitude for increasing complexity. We also report the detection of both syn and anti conformers of vinyl alcohol, with column densities of (1.11 ± 0.08) × 10
14
cm
−2
and (1.3 ± 0.4) × 10
13
cm
−2
, and abundances of (8.2 ± 0.6) × 10
−10
and (9.6 ± 3.0) × 10
−11
, respectively.
Conclusions.
The detection of
n
-propanol, together with the recent discovery of ethanolamine in the ISM, opens the possibility that precursors of lipids according to theories of the origin of life, could have been brought to Earth from outer space.
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