2 As a result, we could generate human iPS cells from human liver progenitor cells only by use of small molecules.2 The human iPS cells were similar to hES cells in morphology, proliferation, surface antigens, gene expression, and epigenetic status of pluripotent cell-specific genes.2 Furthermore, these cells could differentiate into cell types of the three germ layers in vitro and in teratomas.2 Therefore, we designated

the human iPS cells as chemicals-human induced pluripotent stem (ChiPS) cells.2 On the other hand, although Liu et al. did not show the risk evaluation of malignant transformations for the human HM781-36B purchase iPS cells lines that they generated,1 we performed the risk evaluation.2 It was reported that cancer risk for patients

with Down syndrome was less than healthy individuals, and the microvessel density (MVD) within severe combined immunodeficient (SCID) mice in which human iPS cells derived from patients with Down syndrome were transplanted was also less than the MVD in SCID mice Ensartinib in which human iPS cells derived from healthy people were transplanted.3 Therefore, according to the method of Baek et al.,3 by using MVD within SCID mice in which ChiPS cell lines as human iPS cell lines were transplanted, we performed the risk evaluation of malignant transformations for the cell lines. As a result, the MVD in our study2 was equal to the case3 of patients with Down syndrome. Furthermore, we tried to differentiate human normal hepatocytes from ChiPS cells as human iPS cells, according to the method of Liu et al.1 As a result, we could

generate mature hepatocytes 21 days after the initiation of differentiation (Fig. 1). Moreover, according to the method of Liu et al.,1 although we evaluated cytochrome P450 (CYP450) metabolism in ChiPS cell–derived mature hepatocytes, the CYP3A4 and CYP1A2 activity appeared to be the same as in the case of the ihH10 cell line that Liu et al.1 generated. In conclusion, human iPS cells that Liu et al.1 or we2 generated would be useful for the study of liver disease pathogenesis. However, our ChiPS cells2 would have an advantage in clinical applications of human iPS cells. Hisashi Moriguchi* † ‡, Raymond T. Chung†, Makoto Mihara*, Chifumi Sato‡, * Department of Plastic and Reconstructive Surgery, The University of Tokyo 上海皓元 Hospital, Tokyo, Japan, † Gastrointestinal Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, ‡ Department of Analytical Sciences, Tokyo Medical and Dental University, Tokyo, Japan. “
“In recent years, long noncoding RNAs (lncRNAs) have been investigated as a new class of regulators of biological function. A recent study reported that lncRNAs control cell proliferation in hepatocellular carcinoma (HCC). However, the role of lncRNAs in liver regeneration and the overall mechanisms remain largely unknown.

05), and the ultrastructure of EGC was roughly normal in these two groups; 5). The S100B expression in terminal diabetes group was lower than that in terminal control group(P < 0.01). And the dilation of endoplasmic reticulum and swelling of mitochondria in cytoplast can be observed, the filaments decreased seriously. X-396 However, mild vacuolization of mitochondria occured and filaments decreased slightly in cytoplast of the terminal control group; 6). ASGES and CSGES were able not only to accelerate gastric emptying in terminal diabetes group and early diabetes group but also normalize gastric slow waves. The S100B expression, the number

of mitochondria and filaments increased after SGES. The effect of chronic stimulation was superior to acute stimulation. Conclusion: Our date suggested that the delayed gastric emptying due to the growth of age may be related to the activity of EGC. SGES with appropriate parameters

can restore normal gastric slow waves and click here improve delayed gastric emptying in diabetic rats. The mechanism of the effects may be associated with EGC activation. Key Word(s): 1. SGES; 2. diabetes; 3. gastroparesis; 4. EGC; Presenting Author: WU JING Additional Authors: LI XUELIANG, JIA FANGYUAN, XIE BIYUN, LIN LIN Corresponding Author: WU JING Affiliations: First Affiliated Hospital of Nanjing Medical University Objective: Nesfatin-1, product of the precursor NEFA/nucleobindin2 (NUCB2), was initially identified as anorectic hypothalamic neuropeptide. Nesfatin-1 induces a wide spectrum of central actions to stimulate the pituitary-adrenal

axis and sympathetic nervous system and influences visceral functions and emotion. However, not much is known about the effect of nesfatin-1 on gastric acid secretion. Methods: To examine the effect of nesfatin-1 on gastric acid secretion, we injected MCE nesfatin-1 into the lateral brain ventricle in chronically cannulated rats, and observed the gastric acid secretion, the expression and activity of H+/K+-ATPase in different treatment group in rats. Meanwhile, c-Fos immunohistochemistry in brain sections was used to evaluate in vivo neuronal activation by Intracerebroventricular (i.c.v) injection of nesfatin-1. Histamine content in the gastric mucosa of rats in different treatment group was measured by ELISA. And the expression of Histidine decarboxylase (HDC) was examined by RT-PCR and western blot. Results: Intracerebroventricular injection of nesfatin-1 decreased gastric acid output in a dose and time-dependent manner. And the expression and activity of H+/K+-ATPase were also be down-regulated. Nesfatin-1 caused activation of DMV neurons, as evidenced by a 1.37-fold increase in the mean optical density of c-Fos positive DMV neurons in nesfatin-1 treated animals vs. controls. At the same time, the gastric mucosal histamine levels were also down regulated by nesfatin-1.

05), and the ultrastructure of EGC was roughly normal in these two groups; 5). The S100B expression in terminal diabetes group was lower than that in terminal control group(P < 0.01). And the dilation of endoplasmic reticulum and swelling of mitochondria in cytoplast can be observed, the filaments decreased seriously. R788 cost However, mild vacuolization of mitochondria occured and filaments decreased slightly in cytoplast of the terminal control group; 6). ASGES and CSGES were able not only to accelerate gastric emptying in terminal diabetes group and early diabetes group but also normalize gastric slow waves. The S100B expression, the number

of mitochondria and filaments increased after SGES. The effect of chronic stimulation was superior to acute stimulation. Conclusion: Our date suggested that the delayed gastric emptying due to the growth of age may be related to the activity of EGC. SGES with appropriate parameters

can restore normal gastric slow waves and Z-VAD-FMK concentration improve delayed gastric emptying in diabetic rats. The mechanism of the effects may be associated with EGC activation. Key Word(s): 1. SGES; 2. diabetes; 3. gastroparesis; 4. EGC; Presenting Author: WU JING Additional Authors: LI XUELIANG, JIA FANGYUAN, XIE BIYUN, LIN LIN Corresponding Author: WU JING Affiliations: First Affiliated Hospital of Nanjing Medical University Objective: Nesfatin-1, product of the precursor NEFA/nucleobindin2 (NUCB2), was initially identified as anorectic hypothalamic neuropeptide. Nesfatin-1 induces a wide spectrum of central actions to stimulate the pituitary-adrenal

axis and sympathetic nervous system and influences visceral functions and emotion. However, not much is known about the effect of nesfatin-1 on gastric acid secretion. Methods: To examine the effect of nesfatin-1 on gastric acid secretion, we injected MCE公司 nesfatin-1 into the lateral brain ventricle in chronically cannulated rats, and observed the gastric acid secretion, the expression and activity of H+/K+-ATPase in different treatment group in rats. Meanwhile, c-Fos immunohistochemistry in brain sections was used to evaluate in vivo neuronal activation by Intracerebroventricular (i.c.v) injection of nesfatin-1. Histamine content in the gastric mucosa of rats in different treatment group was measured by ELISA. And the expression of Histidine decarboxylase (HDC) was examined by RT-PCR and western blot. Results: Intracerebroventricular injection of nesfatin-1 decreased gastric acid output in a dose and time-dependent manner. And the expression and activity of H+/K+-ATPase were also be down-regulated. Nesfatin-1 caused activation of DMV neurons, as evidenced by a 1.37-fold increase in the mean optical density of c-Fos positive DMV neurons in nesfatin-1 treated animals vs. controls. At the same time, the gastric mucosal histamine levels were also down regulated by nesfatin-1.

This study is to explore the endoscopic and clinical feature of esophageal IMT. Methods: To study CT99021 cell line the endoscopic and clinical features of esophageal inflammatory myofibroblastic tumors (IMT) retrospectively by 2 cases of IMT confirmed by pathological results. Both of patients presented with food impaction. Gastroscopy and endoscopic ultrasound(EUS) were used to detect the esophageal submucosal mass on these 2 patients before surgery. The 2 masses were successfully removed and the diagnosis of IMT was confirmed by pathological results. Results: Esophageal protrusions with narrowed lumen were revealed by gastroscopy. The covering mucosa appeared

to be ulcerative or nodular. In EUS, the layers of esophageal wall can not be clearly identified and presented with heterogeneous mass. The mass appeared to have capsule. In one case, the capsuled was protruded indicating malignance but obviously different from esophageal carcinoma. In addition, IMT has some submucosal features in EUS but apparently different from other common submucosal tumors such as leiomyoma and GIST.

In pathology, there was a dense population of fibroblastic cells with some inflammatory cells including plasma cells, lymphocytes and eosinophils. Tyrosine Kinase Inhibitor Library datasheet The fibroblastic cells extended through the muscular layer to the adventitia. With immunohistochemistry stains, spindle cells were positive for vimentin and diffusely positive for anaplastic lymphoma kinase, SMA and desmin, negative for S-100, CD34 and CD68. Conclusion: Food impaction might be the most common symptom of esophageal IMT. Gastroscopy and EUS has predict value in diagnosis of IMT. The pathology and immunohistochemistry are conclusive for the definite diagnosis. Key Word(s): 1. IMT; 2. endoscopy; 3. EUS; 4. pathology; Presenting Author:

WU SHUANG Additional Authors: LI YUQIN, WANG LIBO, TANG TONGYU, 上海皓元 XU HONG Corresponding Author: WU SHUANG Affiliations: Department of Gastroenterology of 1st Hospital of Jilin University Objective: Colonoscopy is widely used for detection of colorectal neoplasia. However, the rates of detection of neoplasia vary among endoscopists with different withdrawal time. This study was conducted to investigate correlation of the rate of detection and the time taken to withdraw the colonoscope. Methods: Patients(aged from 40 to 60) who underwent colonoscopies from April, 2011 to April 2013 were enrolled. Endoscopists of similar seniority were involved and the same endoscopic device (OLYMPUS EVIS LUCERA 260) were used to all patients. According to previous recommendation, 6 minutes is the minimum length of time to allow adequate inspection.

This study is to explore the endoscopic and clinical feature of esophageal IMT. Methods: To study selleck products the endoscopic and clinical features of esophageal inflammatory myofibroblastic tumors (IMT) retrospectively by 2 cases of IMT confirmed by pathological results. Both of patients presented with food impaction. Gastroscopy and endoscopic ultrasound(EUS) were used to detect the esophageal submucosal mass on these 2 patients before surgery. The 2 masses were successfully removed and the diagnosis of IMT was confirmed by pathological results. Results: Esophageal protrusions with narrowed lumen were revealed by gastroscopy. The covering mucosa appeared

to be ulcerative or nodular. In EUS, the layers of esophageal wall can not be clearly identified and presented with heterogeneous mass. The mass appeared to have capsule. In one case, the capsuled was protruded indicating malignance but obviously different from esophageal carcinoma. In addition, IMT has some submucosal features in EUS but apparently different from other common submucosal tumors such as leiomyoma and GIST.

In pathology, there was a dense population of fibroblastic cells with some inflammatory cells including plasma cells, lymphocytes and eosinophils. selleckchem The fibroblastic cells extended through the muscular layer to the adventitia. With immunohistochemistry stains, spindle cells were positive for vimentin and diffusely positive for anaplastic lymphoma kinase, SMA and desmin, negative for S-100, CD34 and CD68. Conclusion: Food impaction might be the most common symptom of esophageal IMT. Gastroscopy and EUS has predict value in diagnosis of IMT. The pathology and immunohistochemistry are conclusive for the definite diagnosis. Key Word(s): 1. IMT; 2. endoscopy; 3. EUS; 4. pathology; Presenting Author:

WU SHUANG Additional Authors: LI YUQIN, WANG LIBO, TANG TONGYU, MCE公司 XU HONG Corresponding Author: WU SHUANG Affiliations: Department of Gastroenterology of 1st Hospital of Jilin University Objective: Colonoscopy is widely used for detection of colorectal neoplasia. However, the rates of detection of neoplasia vary among endoscopists with different withdrawal time. This study was conducted to investigate correlation of the rate of detection and the time taken to withdraw the colonoscope. Methods: Patients(aged from 40 to 60) who underwent colonoscopies from April, 2011 to April 2013 were enrolled. Endoscopists of similar seniority were involved and the same endoscopic device (OLYMPUS EVIS LUCERA 260) were used to all patients. According to previous recommendation, 6 minutes is the minimum length of time to allow adequate inspection.

5B). In parallel with NRF2 nuclear translocation, a decrease of KEAP1 was observed (Fig. 5A). To mechanistically investigate the role of this pathway, we moved to in vitro experiments and evaluated

cell growth upon NRF2 or KEAP1 silencing in three human HCC cell lines. KEAP1 silencing was associated with increased NRF2 protein levels (Fig. 6C; Supporting Fig. 6C). When cell growth was assessed in the absence or in the presence of oxidative stress (H2O2), we found that NFR2 silencing impaired cell Selleckchem Tanespimycin proliferation, while KEAP1 silencing increased growth rate (Fig. 6A; Supporting Fig. 6A). Analysis of NRF2 target gene expression demonstrated either inhibition or activation of the pathway upon NRF2 or KEAP1 silencing, respectively (Fig. 6B; Supporting Fig. 6B). Since in humans KEAP1 is negatively controlled by miR-200a,[21] which is up-regulated in KRT-19+ lesions and aHCC compared to normal liver (Supporting Table 2, Supporting Fig. 5), we evaluated SB203580 cell growth upon transfection of

a miR-200a mimic. MiR-200a promoted cell growth, recapitulating the effect of KEAP1 silencing (Fig. 6A; Supporting Fig. 6A). The effect of miR-200a modulation was confirmed by its ability to down-regulate KEAP1 both in human and rat HCC cells (Fig. 6C; Supporting Fig. 6C) and to promote the expression of NRF2 target genes (Fig. 6B; Supporting Fig. 6B). Altogether, these results suggest that miR-200a controls the NRF2 pathway, whose activation promotes liver cancer cell growth. Since the role of NRF2 in early and/or intermediate stages of HCC development is still unknown, we aimed at investigating the effect of NRF2 modulation in these stages, characterized by a remarkable NRF2 activation (Fig. 3). 上海皓元 Our previous studies have shown that a 7-day treatment with thyroid hormone (T3) is able to cause a significant reduction in the number of preneoplastic hepatic lesions in rats previously exposed to the R-H model.[22] Based on the above findings, we wished to determine

whether the antitumorigenic activity of T3 could be mediated by NRF2. To this aim, 9 weeks after DENA initiation nodule-bearing rats were fed T3 for 4 and 7 days. While T3 treatment for 7 days caused a 50% reduction in the number of preneoplastic lesions compared to untreated animals, no difference between the two groups was observed at day 4 (Fig. 7A). We evaluated the expression of NRF2 and KEAP1 in microdissected KRT-19+ lesions from 4-day treated or untreated rats, namely, at a time that preceded the loss of preneoplastic nodules. T3 treatment resulted in global reduction of NRF2 expression and in loss of its nuclear localization (Fig. 7B), suggesting that T3 inactivates the NRF2-dependent pathway. This was confirmed by the down-regulation of NRF2 target genes (Fig. 7C).

5B). In parallel with NRF2 nuclear translocation, a decrease of KEAP1 was observed (Fig. 5A). To mechanistically investigate the role of this pathway, we moved to in vitro experiments and evaluated

cell growth upon NRF2 or KEAP1 silencing in three human HCC cell lines. KEAP1 silencing was associated with increased NRF2 protein levels (Fig. 6C; Supporting Fig. 6C). When cell growth was assessed in the absence or in the presence of oxidative stress (H2O2), we found that NFR2 silencing impaired cell AZD8055 cost proliferation, while KEAP1 silencing increased growth rate (Fig. 6A; Supporting Fig. 6A). Analysis of NRF2 target gene expression demonstrated either inhibition or activation of the pathway upon NRF2 or KEAP1 silencing, respectively (Fig. 6B; Supporting Fig. 6B). Since in humans KEAP1 is negatively controlled by miR-200a,[21] which is up-regulated in KRT-19+ lesions and aHCC compared to normal liver (Supporting Table 2, Supporting Fig. 5), we evaluated BTK inhibitor cell growth upon transfection of

a miR-200a mimic. MiR-200a promoted cell growth, recapitulating the effect of KEAP1 silencing (Fig. 6A; Supporting Fig. 6A). The effect of miR-200a modulation was confirmed by its ability to down-regulate KEAP1 both in human and rat HCC cells (Fig. 6C; Supporting Fig. 6C) and to promote the expression of NRF2 target genes (Fig. 6B; Supporting Fig. 6B). Altogether, these results suggest that miR-200a controls the NRF2 pathway, whose activation promotes liver cancer cell growth. Since the role of NRF2 in early and/or intermediate stages of HCC development is still unknown, we aimed at investigating the effect of NRF2 modulation in these stages, characterized by a remarkable NRF2 activation (Fig. 3). MCE公司 Our previous studies have shown that a 7-day treatment with thyroid hormone (T3) is able to cause a significant reduction in the number of preneoplastic hepatic lesions in rats previously exposed to the R-H model.[22] Based on the above findings, we wished to determine

whether the antitumorigenic activity of T3 could be mediated by NRF2. To this aim, 9 weeks after DENA initiation nodule-bearing rats were fed T3 for 4 and 7 days. While T3 treatment for 7 days caused a 50% reduction in the number of preneoplastic lesions compared to untreated animals, no difference between the two groups was observed at day 4 (Fig. 7A). We evaluated the expression of NRF2 and KEAP1 in microdissected KRT-19+ lesions from 4-day treated or untreated rats, namely, at a time that preceded the loss of preneoplastic nodules. T3 treatment resulted in global reduction of NRF2 expression and in loss of its nuclear localization (Fig. 7B), suggesting that T3 inactivates the NRF2-dependent pathway. This was confirmed by the down-regulation of NRF2 target genes (Fig. 7C).

Measuring animal emotions might appear, at first glance, as a difficult goal to achieve. Fortunately, the interest in the field of affective biology has considerably increased recently. As a result, new frameworks have emerged, offering researchers convenient and accurate techniques to measure animal emotional states, including positive

emotions and moods (i.e. long-term diffuse emotional states that are not directly caused by an event; e.g. Désiré, Boissy & Veissier, 2002; Paul, Harding & Mendl, 2005; Boissy et al., 2007; Mendl et al., Selleck RO4929097 2010). The basic principle behind those measures is relatively simple: an animal is assumed to experience a given emotion (e.g. fear) if it shows neurophysiological (e.g. changes in brain activity or in heart rate), behavioural (e.g. facial expression, production of calls, fleeing behaviour) Silmitasertib order and/or cognitive (e.g. increase in attention towards the stimulus, ‘attention bias’) signs of this emotion in a situation presumed to induce it. Therefore, to study a given emotion, a first step consists

in placing the animal in a situation presumed to trigger this emotion and then measuring the corresponding pattern of neurophysiological, behavioural and/or cognitive changes induced. The resulting emotion-specific profile of responses can then be used later as evidence that the emotion is elicited in other situations. I will present here the framework developed by Mendl et al. (2010), one of several useful theories within this field to study emotions (e.g. see also appraisal theories; Désiré et al., 2002). This framework proposes to assess emotions using the measurable components of the organism’s emotional

response (neurophysiological, behavioural and cognitive) through the two dimensions of emotions (valence and arousal; ‘dimensional approach’). As opposed to the ‘discrete emotion approach’, medchemexpress which suggests the existence of a small number of fundamental emotions associated with very specific neurophysiological response patterns, the ‘dimensional approach’ suggests that all types of emotions can be mapped in the space defined by valence and arousal (i.e. by a given combination of these two dimensions). Therefore, neurophysiological, behavioural and cognitive measures reliably associated with a particular location in this two-dimensional space can be used as indicators of the emotion defined by this location. For example, indicators of ‘fear’ will be components reliably associated with negative valence and high arousal, whereas those of ‘contentment’ will be components reliably associated with positive valence and low arousal (Mendl et al., 2010). This approach is useful for the study of animal emotions because it allows researchers to investigate differences between emotional states of low versus high arousal and of positive versus negative valence, without having to infer the specific emotion that the animal is experiencing.

Measuring animal emotions might appear, at first glance, as a difficult goal to achieve. Fortunately, the interest in the field of affective biology has considerably increased recently. As a result, new frameworks have emerged, offering researchers convenient and accurate techniques to measure animal emotional states, including positive

emotions and moods (i.e. long-term diffuse emotional states that are not directly caused by an event; e.g. Désiré, Boissy & Veissier, 2002; Paul, Harding & Mendl, 2005; Boissy et al., 2007; Mendl et al., click here 2010). The basic principle behind those measures is relatively simple: an animal is assumed to experience a given emotion (e.g. fear) if it shows neurophysiological (e.g. changes in brain activity or in heart rate), behavioural (e.g. facial expression, production of calls, fleeing behaviour) www.selleckchem.com/products/U0126.html and/or cognitive (e.g. increase in attention towards the stimulus, ‘attention bias’) signs of this emotion in a situation presumed to induce it. Therefore, to study a given emotion, a first step consists

in placing the animal in a situation presumed to trigger this emotion and then measuring the corresponding pattern of neurophysiological, behavioural and/or cognitive changes induced. The resulting emotion-specific profile of responses can then be used later as evidence that the emotion is elicited in other situations. I will present here the framework developed by Mendl et al. (2010), one of several useful theories within this field to study emotions (e.g. see also appraisal theories; Désiré et al., 2002). This framework proposes to assess emotions using the measurable components of the organism’s emotional

response (neurophysiological, behavioural and cognitive) through the two dimensions of emotions (valence and arousal; ‘dimensional approach’). As opposed to the ‘discrete emotion approach’, MCE which suggests the existence of a small number of fundamental emotions associated with very specific neurophysiological response patterns, the ‘dimensional approach’ suggests that all types of emotions can be mapped in the space defined by valence and arousal (i.e. by a given combination of these two dimensions). Therefore, neurophysiological, behavioural and cognitive measures reliably associated with a particular location in this two-dimensional space can be used as indicators of the emotion defined by this location. For example, indicators of ‘fear’ will be components reliably associated with negative valence and high arousal, whereas those of ‘contentment’ will be components reliably associated with positive valence and low arousal (Mendl et al., 2010). This approach is useful for the study of animal emotions because it allows researchers to investigate differences between emotional states of low versus high arousal and of positive versus negative valence, without having to infer the specific emotion that the animal is experiencing.

Because of the often pronounced differences in colour vision between species, some signals that appear distinct for human observers will not be Selleckchem LY2157299 so for other animal species and vice versa – hence, any exploration of colour mimicry requires consideration of the receiver receptor system. Comparing the coat coloration and patterning of workers from different populations (subspecies) of the common European bumblebee species Bombus terrestris (Linnaeus 1758), there are substantial differences between several distinct populations (Vogt, 1911; Estoup et al., 1996; Velthuis & van Doorn, 2006; Rasmont et al., 2008). For example, Bombus terrestris terrestris

(Linnaeus 1758) from Central Europe, Bombus terrestris dalmatinus (Dalla Torre 1882) from the eastern Mediterranean region and Bombus terrestris audax (Harris 1776) from Great Britain all have a very

similar appearance. Workers from all three populations are predominantly black with two yellow bands, one each on the thorax and abdomen, with a white tip to their abdomen (Fig. 1a). Workers of the Sardinian population, Bombus terrestris sassaricus (Tournier 1890), differ in appearance as they lack the yellow band on the thorax, and have reddish-brown legs. Workers from both the Canary Island Bombus terrestris canariensis (Pérez 1895) and Corsican Bombus terrestris xanthopus (Kriechbaumer 1870) populations entirely lack all yellow bands. Reflectance in the ultraviolet, which is an essential component of the vision of avian insectivores (Cuthill & Bennett, 1993), has not been explored so far, and we endeavour to fill Alvelestat mw this gap here. If it is true that predators learn to avoid bumblebee workers with local, familiar coloration, it is predicted that workers of visually distinct, non-native populations face a 上海皓元 higher local predation risk. In order to test this hypothesis, we evaluated the results from several transplant experiments, to compare the loss rate of workers from native and non-native populations. Choosing a central-place forager like bumblebees has a major advantage compared with previous transplant

studies, which addressed this question using butterflies and mark–recapture techniques (Mallet & Barton, 1989; Kapan, 2001): bumblebee workers return to the nest after each foraging bout, whereas members of many other species have no particular motivation to remain near a location where they have been released; hence differences in recapture rates might in fact reflect differences in propensity to disperse. Using bumblebees, we were able to record the total amount of time each worker spent foraging outside the nest and therefore, crucially, the total amount of time each colour morph was actually exposed to potential predators. We could then compare the loss rates of workers from populations with different colour patterns.