More Like this

1. Multiple paternity in a lek mating system: Females mate multiply when they choose inexperienced sires

   https://doi.org/10.1111/1365-2656.13158  

   Rivers, Pearl R. ; DuVal, Emily H. ; Sheldon, ed., Ben ( December 2019 , Journal of Animal Ecology)

   Multiple mating by females is common and often driven by social constraints on female mate choice. However, females mate with multiple males even in systems without these social constraints and rates of multiple mating tend to be highly variable within and between populations. In lek mating systems, females are able to assess multiple males and their choice is unrestricted by pair bonds or the need for biparental care, yet some females mate with multiple males.

   To better understand the factors affecting variation in multiple mating, we investigated the occurrence of multiple paternity within clutches in a highly polygynous lek mating system.

   Using long‐term data on genetic paternity, survival, social status and individual age from a population of lance‐tailed manakinsChiroxiphia lanceolata, a species where males lek in cooperative alpha‐beta pairs, we tested five non‐exclusive hypotheses about the causes of variation in multiple mating and its benefits in females.

   We found that inexperienced males, including new alphas and rare beta sires, were disproportionately likely to share paternity when they sired any chicks. In contrast, female age (experience) was unrelated to multiple paternity. Multiple mating did not result in higher reproductive success or reduced variance in success for females, and there were neither consistently promiscuousmore »females nor males that consistently shared paternity.

   The occurrence of multiple paternity in this lek mating system was best explained by female choice related to male characteristics that change with male experience. Our results support the hypothesis that there is a developmental component to the occurrence of multiple mating, and suggest females choose to mate multiply when their choices are not optimal.

   « less
2. Demonstration of using two aperture pairs combined with multiple-mode receivers and MIMO signal processing for enhanced tolerance to turbulence and misalignment in a 10  Gbit/s QPSK FSO link

   https://doi.org/10.1364/OL.391120  

   Song, Haoqian ; Li, Long ; Pang, Kai ; Zhang, Runzhou ; Zou, Kaiheng ; Zhao, Zhe ; Du, Jing ; Song, Hao ; Liu, Cong ; Cao, Yinwen ; et al ( May 2020 , Optics Letters)

   We utilize aperture diversity combined with multiple-mode receivers and multiple-input-multiple-output (MIMO) digital signal processing (DSP) to demonstrate enhanced tolerance to atmospheric turbulence and spatial misalignment in a 10 Gbit/s quadrature-phase-shift-keyed (QPSK) free-space optical (FSO) link. Turbulence and misalignment could cause power coupling from the fundamental Gaussian mode into higher-order modes. Therefore, we detect power from multiple modes and use MIMO DSP to enhance the recovery of the original data. In our approach, (a) each of multiple transmitter apertures transmits a single fundamental Gaussian beam carrying the same data stream, (b) each of multiple receiver apertures detects the signals that are coupled from the fundamental Gaussian beams to multiple orbital angular momentum (OAM) modes, and (c) MIMO DSP is used to recover the data over multiple modes and receivers. Our simulation shows that the outage probability could be reduced from$><\#comment/>0.1$to$<<\#comment/>0.01$. Moreover, we experimentally demonstrate the scheme by transmitting two fundamental Gaussian beams carrying the same data stream and recovering the signals on OAM modes 0 and$+1$at each receiver aperture. We measure an up to$\sim <\#comment/>10\mathrm{d}\mathrm{B}$power-penalty reduction for a bit error rate (BER) at the 7% forward error correction limit formore »a 10 Gbit/s QPSK signal.

   « less
3. One internship, two internships, three internships … more!’: exploring the culture of the multiple internship economy

   https://doi.org/10.1080/13639080.2022.2036713  

   Wolfgram, M. ( January 2022 , Journal of education and work)

   Internships are increasingly promoted as a high impact practice to improve students’ post-graduation employment outcomes, and educators often encourage students to participate in multiple internships. Yet, there is a lack of research on the sociocultural contexts associated with multiple internship participation. We present findings about the culture of multiple internship participation – drawing on focus groups and one-year follow-up interviews with students at five colleges in the United States, along with interviews with their educators and an analysis of online documents about multiple internship participation. The evidence documents a particular culture of the multiple internship economy, representing multiple internships as a linear, progressive, goal-oriented cultural project to accumulate a marketable self; also described by anthropologists as a neoliberal conception of the self. This cultural conception of a marketable neoliberal self is comprised of signs – such as narratives of multiple internships – that provide evidence of skills and experiences, of persevering through obstacles, and of ‘hustle’ and a ‘do what it takes’ attitude, which can be deployed to navigate competitive gatekeeping encounters such as employment interviews. Based on these findings, we develop a sociocultural theory of multiple internship participation as a project of neoliberal gatekeeping navigation.
4. Multiple paternity and the number of offspring: A model reveals two major groups of species

   https://doi.org/10.1002/bies.202000247  

   Correia, Hannah E. ; Abebe, Ash ; Dobson, F. Stephen ( January 2021 , BioEssays)

   Parentage analyses via microsatellite markers have revealed multiple paternity within the broods of polytocous species of mammals, reptiles, amphibians, fishes and invertebrates. The widespread phenomenon of multiple paternity may have attending relationships with such evolutionary processes as sexual selection and kin selection. However, just how much multiple paternity should a species exhibit? We developed Bayesian null models of how multiple paternity relates to brood sizes. For each of 114 species with published data on brood sizes and numbers of sires, we compared our null model estimates to published frequencies of multiple paternity. The majority of species fell close to our null model, especially among fish and invertebrate species. Some species, however, had low probabilities of multiple paternity, far from the predictions of the null model, likely due to sexual selection and environmental constraints. We suggest a major division among species’ mating systems between those with close to random mating and high levels of multiple paternity, and those with constraints that produce low levels of multiple paternity.
5. Holographic particle localization under multiple scattering

   https://doi.org/doi:10.1117/1.ap.1.3.036003  

   Tahir, W. ; Tian, L. ; Kamilov, U. ( January 2019 , SPIE journal)

   We introduce a computational framework that incorporates multiple scattering for large-scale three-dimensional (3-D) particle localization using single-shot in-line holography. Traditional holographic techniques rely on single-scattering models that become inaccurate under high particle densities and large refractive index contrasts. Existing multiple scattering solvers become computationally prohibitive for large-scale problems, which comprise millions of voxels within the scattering volume. Our approach overcomes the computational bottleneck by slicewise computation of multiple scattering under an efficient recursive framework. In the forward model, each recursion estimates the next higher-order multiple scattered field among the object slices. In the inverse model, each order of scattering is recursively estimated by a nonlinear optimization procedure. This nonlinear inverse model is further supplemented by a sparsity promoting procedure that is particularly effective in localizing 3-D distributed particles. We show that our multiple-scattering model leads to significant improvement in the quality of 3-D localization compared to traditional methods based on single scattering approximation. Our experiments demonstrate robust inverse multiple scattering, allowing reconstruction of 100 million voxels from a single 1-megapixel hologram with a sparsity prior. The performance bound of our approach is quantified in simulation and validated experimentally. Our work promises utilization of multiple scattering for versatile large-scale applications.