This paper studies the effect of online product reviews on different players in a channel structure. We consider a retailer selling two substitutable products produced by different manufacturers, and ...the products differ in both their qualities and fits to consumers' needs. Online product reviews provide additional information for consumers to mitigate the uncertainty about the quality of a product and about its fit to consumers' needs. We show that the effect of reviews on the upstream competition between the manufacturers is critical in understanding which firms gain and which firms lose. The upstream competition is affected in fundamentally different ways by quality information and fit information, and each information type has different implications for the retailer and manufacturers. Quality information homogenizes consumers' perceived utility differences between the two products and increases the upstream competition, which benefits the retailer but hurts the manufacturers. Fit information heterogenizes consumers' estimated fits to the products and softens the upstream competition, which hurts the retailer but benefits the manufacturers. Furthermore, reviews may also alter the nature of upstream competition from one in which consumers' own assessment on the quality dimension plays a dominant role in consumers' comparative evaluation of products to one in which fit dimension plays a dominant role. If manufacturers do not respond strategically to reviews and keep the same wholesale prices regardless of reviews (i.e., the upstream competition is assumed to be unaffected by reviews), then, we show that reviews never hurt the retailer and the manufacturer with favorable reviews, and never benefit the manufacturer with unfavorable reviews, a finding that demonstrates why reviews' effect on upstream competition is critical for firms in online marketplaces.
Online retailing is dominated by a channel structure in which a retailer either buys products from competing manufacturers and resells to consumers (wholesale scheme) or lets manufacturers sell ...directly to consumers on its platform for a commission (platform scheme). Easy access to publicly available third-party information such as product reviews that facilitate consumers’ purchase decisions is another distinctive and ubiquitous characteristic of online retailing. We show that retailers can use the upstream pricing scheme, wholesale or platform, as a strategic tool to benefit from third-party information. Information on the quality dimension homogenizes consumers’ perceived utility differences between competing products and increases the upstream competition, which benefits the wholesale-based retailer but hurts the platform-based retailer. Information on the fit dimension, in constrast, heterogenizes consumers’ estimated fits to the products and softens the upstream competition, which hurts the wholesale-based retailer but benefits the platform-based retailer. Consequently, when the precision of the third-party information is high (low), a retailer can benefit from third-party information by adopting the wholesale (platform) scheme if the quality dimension plays a dominant role and by adopting the platform (wholesale) scheme if the fit dimension is dominant. Furthermore, the effect of precision improvement on the retailer’s profit depends on the pricing-scheme choice and the relative importance of quality and fit attributes in consumers’ evaluations of products. For instance, when the fit dimension is dominant, increasing the precision can hurt the wholesale-based retailer but benefit the platform-based retailer.
Flowers open at sunrise and close at sunset, establishing a circadian floral movement rhythm to facilitate pollination as part of reproduction. By the coordination of endogenous factors and ...environmental stimuli, such as circadian clock, photoperiod, light and temperature, an appropriate floral movement rhythm has been established; however, the underlying mechanisms remain unclear.
In our study, we use waterlily as a model which represents an early-diverging grade of flowering plants, and we aim to reveal the general mechanism of flower actions. We found that the intermediate segment of petal cells of waterlily are highly flexible, followed by a circadian cell expansion upon photoperiod stimuli. Auxin causes constitutively flower opening while auxin inhibitor suppresses opening event. Subsequent transcriptome profiles generated from waterlily's intermediate segment of petals at different day-time points showed that auxin is a crucial phytohormone required for floral movement rhythm via the coordination of YUCCA-controlled auxin synthesis, GH3-mediated auxin homeostasis, PIN and ABCB-dependent auxin efflux as well as TIR/AFB-AUX/IAA- and SAUR-triggered auxin signaling. Genes involved in cell wall organization were downstream of auxin events, resulting in the output phenotypes of rapid cell expansion during flower opening and cell shrinkage at flower closure stage.
Collectively, our data demonstrate a central regulatory role of auxin in floral movement rhythm and provide a global understanding of flower action in waterlily, which could be a conserved feature of angiosperms.
Hybrid inorganic-organic perovskites have quickly evolved as a promising group of materials for solar cells and optoelectronic applications mainly owing to the inexpensive materials, relatively ...simple and versatile fabrication and high power conversion efficiency (PCE). The certified energy conversion efficiency for perovskite solar cell (PSC) has reached above 20%, which is compatible to the current best for commercial applications. However, long-term stabilities of the materials and devices remain to be the biggest challenging issue for realistic implementation of the PSCs. This article discusses the key issues related to the stability of perovskite absorbing layer including crystal structural stability, chemical stability under moisture, oxygen, illumination and interface reaction, effects of electron-transporting materials (ETM), hole-transporting materials (HTM), contact electrodes, ion migration and preparation conditions. Towards the end, prospective strategies for improving the stability of PSCs are also briefly discussed and summarized. We focus on recent understanding of the stability of materials and devices and our perspectives about the strategies for the stability improvement.
Display omitted
•Progress in stabilizing hybrid perovskite solar cells (PSCs) is reviewed.•Key issues related to the stability of perovskite components are evaluated.•Optimizing multiple factors associated with component structures is essential.•Strategies for improving the stability of PSCs are discussed and summarized.
In this article, we consider the following Choquard system in
where
,
denotes
if
and
if
,
is a Riesz potential. By analyzing the asymptotic behavior of Riesz potential energy, we prove that minimal ...action sign-changing solutions have an odd symmetry with respect to the a hyperplane when
is either close to 0 or close to
. Our results can be regarded as a generalization of the results by Ruiz et al.
The B-BOX (BBX) proteins are the class of zinc-finger transcription factors and can regulate plant growth, development, and endure stress response. In plants, the BBX gene family has been identified ...in Arabidopsis, rice, and tomato. However, no systematic analysis of BBX genes has been undertaken in grapevine.
In this study, 24 grapevine BBX (VvBBX) genes were identified by comprehensive bioinformatics analysis. Subsequently, the chromosomal localizations, gene structure, conserved domains, phylogenetic relationship, gene duplication, and cis-acting elements were analyzed. Phylogenetic analysis divided VvBBX genes into five subgroups. Numerous cis-acting elements related to plant development, hormone and/or stress responses were identified in the promoter of the VvBBX genes. The tissue-specific expressional dynamics of VvBBX genes demonstrated that VvBBXs might play important role in plant growth and development. The transcript analysis from transcriptome data and qRT-PCR inferred that 11 VvBBX genes were down-regulated in different fruit developmental stages, while three VvBBX genes were up-regulated. It is also speculated that VvBBX genes might be involved in multiple hormone signaling (ABA, ethylene, GA3, and CPPU) as transcriptional regulators to modulate berry development and ripening. VvBBX22 seems to be responsive to multiple hormone signaling, including ABA, ethylene GA3, and CPPU. Some VvBBX genes were strongly induced by Cu, salt, waterlogging, and drought stress treatment. Furthermore, the expression of VvBBX22 proposed its involvement in multiple functions, including leaf senescence, abiotic stress responses, fruit development, and hormone response.
Our results will provide the reference for functional studies of BBX gene family, and highlight its functions in grapevine berry development and ripening. The results will help us to better understand the complexity of the BBX gene family in abiotic stress tolerance and provide valuable information for future functional characterization of specific genes in grapevine.
The anionic peroxidases play an important role in a variety of plant physiological processes. We characterized and isolated the Zmap promoter (PZmap) at the 5' flanking region in order to better ...understand the regulatory mechanisms of Zmap gene expression. A series of PZmap deletion derivatives, termed a1 -a6, at positions -1694, -1394, -1138, -784, -527 and -221 from the translation start site were blended to the β-glucuronidase reporter gene. Agrobacterium-mediated transformation method was used to study each deletion construct in tobaccos. Sequence analysis showed that several cis-acting elements (MYB binding site, Box-II, a TGACG-element, a CGTCA-element and a low temperature responsive element) were located within the promoter. Deletion analysis suggested the sequence between -1,694 and -1394bp may contain cis-elements associated with GUS up regulation. The MYB binding site (-757) might act as a negative drought-responsive element. There might be repressor elements located in the region (-1,694 to -1394bp) to repress Zmap expression under 4°C. The characterized promoter would be an ideal candidate for genetic engineering for improving the resistance of maize to different stressors.
In this paper, we consider the quasilinear Schrödinger system in
N
≥
3
:
{
−
Δ
u
+
A
(
x
)
u
−
1
2
Δ
(
u
2
)
u
=
2
α
α
+
β
|
u
|
α
−
2
u
|
v
|
β
,
−
Δ
v
+
B
v
−
1
2
Δ
(
v
2
)
v
=
2
β
α
+
β
|
u
|
α
|
...v
|
β
−
2
v
,
where
α
,
β
>
1
,
2
<
α
+
β
<
4
N
N
−
2
,
B
>
0
is a constant. By using a constrained minimization on Nehari–Pohožaev set, for any given integer
s
≥
2
, we construct a non-radially symmetrical nodal solution with its
2
s
nodal domains.
We investigate a fractional Schrödinger-Poisson system with strong singularity as follows:
where
with
,
and
. When
and
satisfy certain conditions, existence and uniqueness of positive solution
are ...established via variational method and Nehari method. We also describe the asymptotic behaviour of
as
Acute diarrhea is still a common and serious disease. The causes of acute diarrhea are very complicated. Therefore, we need to find a medicine to control diarrhea symptoms, save time for diagnosis of ...pathogens, and prevent drug abuse. Ellagic acid (EA), a natural polyphenol drug, has anti-diarrhea effects. However, the action mechanisms of EA for non-specific diarrhea have not been characterized.
To study the mechanisms of EA, mice were divided into four groups. Group C were intraperitoneally injected with 0.1 ml physiological saline and orally given 0.2 ml physiological saline, and then after experiment began 0.5 h, orally administered 0.3 ml physiological saline. Group D were intraperitoneally injected with 0.1 ml physiological saline and orally given 0.2 ml castor oil, and then after experiment began 0.5 h, orally administered 0.3 ml physiological saline. Group E were intraperitoneally injected with 0.1 ml physiological saline and orally given 0.2 ml castor oil, and then after experiment began 0.5 h, orally administered 0.3 ml EA (10 mg/ml). Group V were intraperitoneally injected with 0.1ml GW9662 (1m g/ml) and orally given 0.2 ml castor oil, and then after experiment began 0.5 h, orally administered 0.3 ml EA (10 mg/ml). Transcriptome were performed on ileum tissues of mice in group D and E. Histological examination and qRT-PCR were performed on ileum tissues of mice in group C, D, E, and V.
We found that a total of 273 differentially expressed genes (DEGs) were obtained, including 160 up-regulated DEGs and 113 down-regulated DEGs. The DEGs were enriched in 458 Gene Ontology (GO) terms and 15 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. The peroxisome proliferator activated receptor (PPAR) signaling pathway was the most significantly enriched in KEGG pathways. We used the PPAR-specific antagonist GW9662 to validate the anti-diarrhea and anti-inflammatory effect of EA in group V compared with group E. Conclusively, EA protected ileums against castor oil-induced inflammation and diarrhea by activating the PPAR signaling pathway and a method was used to study the mechanism of EA.
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