Eggs, incubation and hatching asynchrony in gulls

Birds can influence the embryonic development through incubation behaviour because avian embryos develop using parent’s body heat. Although previous studies assumed that incubation behaviour influences hatching patterns, few studies have studied the effect of incubation behaviour during egg-laying and early incubation on hatching patterns due to difficulties to determine onset of incubation during egg-laying. I investigated whether incubation behaviour during egg-laying and early incubation affects hatching patterns in gulls using measurements of mean nest attendance and daily change of nest attendance. Hatching patterns were influenced by incubation behaviour during egg-laying and early incubation behaviour. As parents spent more time in their nests, a brood hatched more synchronously and hatching success of the first-laid eggs increased when gulls laid relatively smaller first-laid eggs than other pairs. Within-clutch variation in eggshell colour related to daily change of incubation behaviour. This might relate to hormonal change during egg-laying. Increase of prolactin initiates incubation and accompanies decline of steroid hormones which relate to accumulation of eggshell pigments. Hatching patterns may also be influenced by accelerated development of last-laid eggs. When eggs were swapped to increase interval between eggs, last-laid eggs of herring gulls accelerated their development to catch up. Accelerated development may increase the survival of chicks from last-laid eggs by reducing the disadvantage of small size within a clutch. However, the costs of accelerated development seem to appear during the embryonic period. Hatching success was low in eggs with accelerated development, although there were no differences in growth rate and early nestling survival between accelerated and control last-laid eggs. Eggshell characteristics might be a factor affecting hatching patterns because they are related to embryonic metabolism. Hatching duration was not related to eggshell thickness and total functional area, but chicks which hatched from eggs with higher proportion of mammilllary cone contact area took longer to hatch. Chicks hatched from thicker eggshells showed longer “head plus bill” at hatching and grew faster in skeleton size after hatching. Diet during egg-laying and early incubation affected nest attendance. Females which consumed more marine food during egg formation had lower nest attendance during egg-laying and early incubation. This may relate to longer foraging time required to obtain marine food. In conclusion, this thesis suggests that parents can influence hatching patterns by altering incubation behaviour during egg-laying and early incubation and hatching patterns also may be affected by accelerated development of last-laid eggs, diet during egg-laying and early incubation and eggshell characteristics (proportion of mammillary cone contact area)

Comparing Generation Y Hotel Employees in the United States and China

Millennials will represent 75% of the global workforce by 2025. They were born and raised in an era of rapid technological development, better access to education, and growing globalization. They are often characterized as protected by Baby Boomer parents and society. They are technologically-savvy, achievement-oriented, team-oriented, job-hoppers, and focused on life-balance. It is essential to understand their values in term of work attitudes and behaviors. Employees’ commitment to customer service is particularly important in the hotel sector as it results in greater customer satisfaction and loyalty as well as better service quality. We surveyed hotel employees in the United States and China to see if they might differ in terms of their work attitude and behaviors. Millennial employees in both cultures expressed a solid commitment to customer service and their attitudes towards power distance, empowerment, employee voice, and team member exchange were similar. The distinct difference was considering how these factors might predict employees’ commitment to customer service, where team member exchange was the most significant predictor for U. S. employees while employee voice was the most significant predictor for the Chinese hotel employees. The findings of this study will help hotel managers understand Generation Y’s values in term of work attitudes and behaviors in a cross-cultural workplace

Weak log-majorization and inequalities of power means

As non-commutative versions of the quasi-arithmetic mean, we consider the Lim-P\'{a}lfia's power mean, R\'{e}nyi right mean and R\'{e}nyi power means. We prove that the Lim-P\'{a}lfia's power mean of order $t \in [-1,0)$ is weakly log-majorized by the log-Euclidean mean and fulfills the Ando-Hiai inequality. We establish the log-majorization relationship between the R\'{e}nyi relative entropy and the product of square roots of given variables. Furthermore, we show the norm inequalities among power means and provide the boundedness of R\'{e}nyi power mean in terms of the quasi-arithmetic mean.Comment: 18 page

Extending satisfaction and loyalty research with a longitudinal perspective

This study examines the relationship between customer satisfaction and loyalty based on two dimensions of loyalty: attitudinal loyalty and behavioral loyalty. By measuring a traveler’s actual future behavior on a longitudinal perspective rather than just at a cross-sectional perspective, this research seeks to contribute to develop theoretical frameworks and quality measures of customer loyalty. The proposed model was tested in a hotel setting with structural equation analysis with the results showing that customer satisfaction is an important antecedent to attitudinal loyalty. Customer satisfaction and attitudinal loyalty were found to not be related to behavioral loyalty. Theoretical and practical implications of the study are discussed

The pricing for same-day arrival guests in the hotel industry

The objective of this study was to recognize the impact on pricing dynamics that elements such as reservation channels, price decision makers, and pricing for same-day and very late (after 11 PM) same-day arrival guests. The data was collected via a random sample from a list of 3,000 hotels provided by Smith Travel Research, with 283 responses being analyzed. Though this is an exploratory study, it fills a need in the hospitality literature for empirical research, as it reveals hotels’ pricing patterns for same-day arrival guests. This study enables managers and scholars to form a better understanding of hotels’ actual pricing for same-day arrival guests. Researchers can thus have a starting point for developing models that can empirically demonstrate what pricing strategies are effective for same-day arrival guests

The Acquisition of Plastids/Phototrophy in Heterotrophic Dinoflagellates

Several dinoflagellates are known to practice acquired phototrophy by either hosting intact algal endosymbionts or retaining plastids. The acquisition of phototrophy in dinoflagellates appears to occur independently over a variety of orders, rather than being restricted to any specific order(s). While dinoflagellates with intact algal cells host endosymbionts of cyanobacteria, pelagophyte, prasinophyte or dictyochophyte, most organelle-retaining dinoflagellates acquire plastids from cryptophytes. In dinoflagellates with acquired phototrophy, the mechanism by which symbionts or plastids are obtained has not been well studied at sub-cellular or ultrastructural level, and thus little is known regarding their mechanism to sequester and maintain photosynthetic structures, except for three cases, Amphidinium poecilochroum, Gymnodinium aeruginosum, and Dinophysis caudata with peduncle feeding. Dinoflagellates with acquired phototrophy display different degrees of reduction of the retained endosymbiont and organelles, ranging from those which contain intact whole algal cells (e.g. green Noctiluca scintillans), to those which have retained almost a full complement of organelles (e.g., Amphidinium poecilochroum and Podolampas bipes), to those in which only the plastids remain (e.g., Amphidinium wigrense and Dinophysis spp.). A series of events leading to acquisition and subsequent degeneration of a whole-cell endosymbiont have been widely recognized as evolutionary pathway of the acquisition of plastids. However, recent work on D. caudata suggests that acquisition of phototrophy by predation (i.e. kleptoplastidy) may be a mechanism and evolutionary pathway through which plastids originated in dinoflagellates with ‘foreign’ plastids other than the ‘typical’ peridinin-type plastids. Most organelle-retaining dinoflagellates are facultative mixotrophs, with Dinophysis species and an undescribed Antarctic dinoflagellate being the only obligate mixotrophs known so far. The establishment of dinoflagellates with acquired phototrophy in cultures and careful research using the cultures would help improve our knowledge of the evolution of the dinoflagellate plastids and their ecophysiology

A Generalized Framework for Video Instance Segmentation

The handling of long videos with complex and occluded sequences has recently emerged as a new challenge in the video instance segmentation (VIS) community. However, existing methods have limitations in addressing this challenge. We argue that the biggest bottleneck in current approaches is the discrepancy between training and inference. To effectively bridge this gap, we propose a Generalized framework for VIS, namely GenVIS, that achieves state-of-the-art performance on challenging benchmarks without designing complicated architectures or requiring extra post-processing. The key contribution of GenVIS is the learning strategy, which includes a query-based training pipeline for sequential learning with a novel target label assignment. Additionally, we introduce a memory that effectively acquires information from previous states. Thanks to the new perspective, which focuses on building relationships between separate frames or clips, GenVIS can be flexibly executed in both online and semi-online manner. We evaluate our approach on popular VIS benchmarks, achieving state-of-the-art results on YouTube-VIS 2019/2021/2022 and Occluded VIS (OVIS). Notably, we greatly outperform the state-of-the-art on the long VIS benchmark (OVIS), improving 5.6 AP with ResNet-50 backbone. Code is available at https://github.com/miranheo/GenVIS.Comment: CVPR 202