Late-Preterm and Full-Term Infant Sleep: Relations with Maternal Cognitions and Nocturnal Behaviors

Approximately 13% of infants born in the United States each year are delivered prematurely, defined as prior to 37 weeks gestation. Among these premature infants, 84% are born between 32 and 36 weeks gestation (Kelly, 2006). Past research has found that the sleep/wake patterns of late-preterm and full-term infants are different (Gossel-Symank, Grimmer, Korte, & Siegmund, 2004; Ingersoll & Thoman, 1999; Ju et al., 1991). However, little is known about psychosocial factors (i.e., maternal sleep-related cognitions and nocturnal behaviors) that may contribute to differences between late-preterm and full-term infant sleep. Few studies have investigated the relations among infant sleep behavior, mothers\u27 cognitions about infant sleep, and mothers\u27 sleep-related behaviors in mothers of full-term and late-preterm infants. Information about these relations might contribute to an understanding of why late-preterm infants might sleep less well than full-term infants.;Results of this study indicated that while not extensive, a few sleep differences do exist between late-preterm and full-term infants at 6 months of age, with late-preterm infants sleeping more during the day than full-term infants. However, relations between infant sleep and maternal cognitions and nocturnal behaviors are less clear. The current sample of late-preterm infant mothers did not endorse cognitions nor participate in nocturnal behaviors that had been previously associated with poorer infant sleep patterns. In some cases, full-term infant mothers were more likely to report certain cognitions (e.g., doubt) than late-preterm infant mothers. This could be related to the psychopathology that was reported in the current sample of full-term infant mothers, including depression. However, late-preterm infant mothers were more vigilant at night than full-term infant mothers, supporting the idea of a slight maternal expectation of infant vulnerability.;Maternal expectations of premature infants in general were also not different between groups with late-preterm infant mothers actually rating unfamiliar full-term infants less favorably than unfamiliar premature labeled infants. While contradictory to what was hypothesized, the findings are in line with research supporting the idea that positive experiences the mothers have had with their own infants would override any negative beliefs held about premature infants. Finally, maternal expectations of infant development also did not differ as was hypothesized. In fact, mothers in the entire sample tended to be accurate reporters of their infant\u27s developmental abilities.;The development of sleep is one of the most important and dramatic processes of infancy and early childhood. The development of sleep/wake patterns in premature infants as an area of research is one that is sparse and the results incongruent. Research investigating sleep in late-premature infants is even less available. Thus, while the current study did not yield a wide range of significant results it is an important first step in continuing to understand the development of sleep patterns in late-premature infants

Isolation and analysis of the genetic diversity of repertoires of VSG expression site containing telomeres from Trypanosoma brucei gambiense, T. b. brucei and T. equiperdum

Background African trypanosomes (including Trypanosoma brucei) are unicellular parasites which multiply in the mammalian bloodstream. T. brucei has about twenty telomeric bloodstream form Variant Surface Glycoprotein (VSG) expression sites (BESs), of which one is expressed at a time in a mutually exclusive fashion. BESs are polycistronic transcription units, containing a variety of families of expression site associated genes (ESAG s) in addition to the telomeric VSG. These polymorphic ESAG families are thought to play a role in parasite-host adaptation, and it has been proposed that ESAG diversity might be related to host range. Analysis of the genetic diversity of these telomeric gene families has been confounded by the underrepresentation of telomeric sequences in standard libraries. We have previously developed a method to selectively isolate sets of trypanosome BES containing telomeres using Transformation associated recombination (TAR) cloning in yeast. Results Here we describe the isolation of repertoires of BES containing telomeres from three trypanosome subspecies: Trypanosoma brucei gambiense DAL 972 (causative agent of West-African trypanosomiasis), T. b. brucei EATRO 2340 (a nonhuman infective strain) and T. equiperdum STIB 818 (which causes a sexually transmitted disease in equines). We have sequenced and analysed the genetic diversity at four BES loci (BES promoter region, ESAG6, ESAG5 and ESAG2) from these three trypanosome BES repertoires. Conclusion With the exception of ESAG2, the BES sequence repertoires derived from T. b. gambiense are both less diverse than and nearly reciprocally monophyletic relative to those from T. b. brucei and T. equiperdum. Furthermore, although we find evidence for adaptive evolution in all three ESAG repertoires in T. b. brucei and T. equiperdum, only ESAG2 appears to be under diversifying selection in T. b. gambiense. This low level of variation in the T. b. gambiense BES sequence repertoires is consistent both with the relatively narrow host range of this subspecies and its apparent long-term clonality. However, our data does not show a clear correlation between size of trypanosome host range and either number of BESs or extent of ESAG genetic diversity

Testing the stability of fundamental constants with the 199Hg+ single-ion optical clock

Over a two-year duration, we have compared the frequency of the 199Hg+ 5d106s 2S 1/2 (F=0) 5d9 6s2 2D 5/2 (F=2) electric-quadrupole transition at 282 nm with the frequency of the ground-state hyperfine splitting in neutral 133Cs. These measurements show that any fractional time variation of the ratio nu(Cs)/nu(Hg) between the two frequencies is smaller than +/- 7 10^-15 / yr (1 sigma uncertainty). According to recent atomic structure calculations, this sets an upper limit to a possible fractional time variation of g(Cs) m_e / m_p alpha^6.0 at the same level.Comment: 4 pages with 3 figures. RevTeX 4, Submitted to Phys. Rev. Let

Cold atom Clocks and Applications

This paper describes advances in microwave frequency standards using laser-cooled atoms at BNM-SYRTE. First, recent improvements of the $^{133}$Cs and $^{87}$Rb atomic fountains are described. Thanks to the routine use of a cryogenic sapphire oscillator as an ultra-stable local frequency reference, a fountain frequency instability of $1.6\times 10^{-14}\tau^{-1/2}$ where $\tau$ is the measurement time in seconds is measured. The second advance is a powerful method to control the frequency shift due to cold collisions. These two advances lead to a frequency stability of $2\times 10^{-16}$ at $50,000s for the first time for primary standards. In addition, these clocks realize the SI second with an accuracy of$7\times 10^{-16}$, one order of magnitude below that of uncooled devices. In a second part, we describe tests of possible variations of fundamental constants using$^{87}$Rb and$^{133}$Cs fountains. Finally we give an update on the cold atom space clock PHARAO developed in collaboration with CNES. This clock is one of the main instruments of the ACES/ESA mission which is scheduled to fly on board the International Space Station in 2008, enabling a new generation of relativity tests.Comment: 30 pages, 11 figure

Telomeric expression sites are highly conserved in trypanosoma brucei

Subtelomeric regions are often under-represented in genome sequences of eukaryotes. One of the best known examples of the use of telomere proximity for adaptive purposes are the bloodstream expression sites (BESs) of the African trypanosome Trypanosoma brucei. To enhance our understanding of BES structure and function in host adaptation and immune evasion, the BES repertoire from the Lister 427 strain of T. brucei were independently tagged and sequenced. BESs are polymorphic in size and structure but reveal a surprisingly conserved architecture in the context of extensive recombination. Very small BESs do exist and many functioning BESs do not contain the full complement of expression site associated genes (ESAGs). The consequences of duplicated or missing ESAGs, including ESAG9, a newly named ESAG12, and additional variant surface glycoprotein genes (VSGs) were evaluated by functional assays after BESs were tagged with a drug-resistance gene. Phylogenetic analysis of constituent ESAG families suggests that BESs are sequence mosaics and that extensive recombination has shaped the evolution of the BES repertoire. This work opens important perspectives in understanding the molecular mechanisms of antigenic variation, a widely used strategy for immune evasion in pathogens, and telomere biology

The type IIb SN 2008ax: spectral and light curve evolution

We present spectroscopy and photometry of the He-rich supernova (SN) 2008ax. The early-time spectra show prominent P-Cygni H lines, which decrease with time and disappear completely about two months after the explosion. In the same period He I lines become the most prominent spectral features. SN 2008ax displays the ordinary spectral evolution of a type IIb supernova. A stringent pre-discovery limit constrains the time of the shock breakout of SN 2008ax to within only a few hours. Its light curve, which peaks in the B band about 20 days after the explosion, strongly resembles that of other He-rich core-collapse supernovae. The observed evolution of SN 2008ax is consistent with the explosion of a young Wolf-Rayet (of WNL type) star, which had retained a thin, low-mass shell of its original H envelope. The overall characteristics of SN 2008ax are reminiscent of those of SN 1993J, except for a likely smaller H mass. This may account for the findings that the progenitor of SN 2008ax was a WNL star and not a K supergiant as in the case of SN 1993J, that a prominent early-time peak is missing in the light curve of SN 2008ax, and that Halpha is observed at higher velocities in SN 2008ax than in SN 1993J.Comment: 10 pages, including 8 figures and 4 tables. Accepted for publication in MNRA

Secret seducers - True tales of pimps in the red light district of Amsterdam

At the end of the 1990s, a moral panic erupted in the Netherlands about the phenomenon of what came to be known as 'loverboys'. The suspicion was that a growing number of Dutch girls were being groomed by handsome young men who employed all sorts of devious methods to prepare their girlfriends for life as a prostitute. Stories about a new generation of pimps, often of Moroccan origin, regularly appeared in the Dutch media. In this article, based on ethnographic fieldwork on pimps operating in the red-light district of Amsterdam, we describe the ways in which these young men operate and how they justify their behaviour. On the basis of empirical research we intend to present a more realistic picture of what goes on in the prostitution industry and highlight the discrepancy between what is reported in the media and what is actually happening in the prostitution sector. We also examine the background to the moral panic about loverboys and the ways in which these young men were supposedly able to induce many young girls into becoming prostitutes

Early observations of the nearby type Ia supernova SN 2015F

We present photometry and time-series spectroscopy of the nearby type Ia supernova (SN Ia) SN 2015F over $-16$ days to $+80$ days relative to maximum light, obtained as part of the Public ESO Spectroscopic Survey of Transient Objects (PESSTO). SN 2015F is a slightly sub-luminous SN Ia with a decline rate of $\Delta m15(B)=1.35 \pm 0.03$ mag, placing it in the region between normal and SN 1991bg-like events. Our densely-sampled photometric data place tight constraints on the epoch of first light and form of the early-time light curve. The spectra exhibit photospheric C II $\lambda 6580$ absorption until $-4$ days, and high-velocity Ca II is particularly strong at $14000$ km s$^{-1}$, suggesting mixing in the outermost layers of the SN ejecta. Although unusual in SN Ia spectra, including V II in the modelling significantly improves the spectral fits. Intriguingly, we detect an absorption feature at $\sim$6800 \AA\ that persists until maximum light. Our favoured explanation for this line is photospheric Al II, which has never been claimed before in SNe Ia, although detached high-velocity C II material could also be responsible. In both cases the absorbing material seems to be confined to a relatively narrow region in velocity space. The nucleosynthesis of detectable amounts of Al II would argue against a low-metallicity white dwarf progenitor. We also show that this 6800 \AA\ feature is weakly present in other normal SN Ia events, and common in the SN 1991bg-like sub-class