There are rich plant resources on the islands, however, fresh water sources are ample, check details and the surrounding sea is marked by high marine productivity and a wealth of seaweeds, shellfish, fish, seabirds, seals,

sea lions, and cetaceans. The westernmost of the northern Channel Islands is San Miguel, located 44 km from the mainland. Today, San Miguel is a maximum of 14 km long and 8 km wide, with a total land area of roughly 37 km2. Cloaked mostly in calcareous sand dunes and scrub vegetation, the island landscape consists of a series of uplifted marine terraces separated by intervening slopes that mark the location of ancient sea cliffs. Rising seas have submerged the shorelines where the island’s earliest maritime peoples probably spent most of their time, but an intensive search of springs,

caves, toolstone sources, and other landforms that drew early islanders into the interior has identified scores of shell middens and scatters of stone tools left behind by Paleocoastal peoples between about 12,200 and 8000 years ago (Braje et al., 2013, Erlandson and Rick, 2008, Erlandson et al., 2011a, Erlandson et al., 2011b, Rick et al., 2013a and Rick et al., 2013b). Some of these Paleocoastal sites are quite large, including a relatively GDC0199 shallow site complex at Cardwell Bluffs dated between ∼12,200 and 11,300 years old that covers an area of ∼180,000 m2 (600 m × 300 m). After sea level rise slowed about 7500 years ago, hundreds of denser and deeper shell middens

were created by the Island Chumash, who lived on San Miguel until they Tangeritin were removed to mainland missions in the early 1800s. By the mid-1800s, thousands of sheep and other domestic livestock were introduced to the island, causing rapid and widespread vegetation loss, dune destabilization, and soil erosion (Erlandson et al., 2005a). Despite this heavy erosion, early archeological surveys on San Miguel documented vast shell midden deposits that formed a virtually continuous blanket of anthropogenic soils along the island’s north coast (Rogers, 1929; see Fig. 4). The south coast appeared to have been much more sparsely occupied until large sheets of windblown sand deposited in historic times were dissected by recent erosion that has exposed scores of shell middens spanning at least the past 9500 years (Braje, 2010 and Braje et al., 2005). Study of San Miguel shell middens suggests that the island was continuously occupied for at least 12,000 years. The island landscape has been fundamentally changed by human occupation for millennia, potentially beginning with the extinction of the island mammoths. Terminal Pleistocene middens on San Miguel and Santa Rosa islands show that a diverse array of seabirds, waterfowl, shellfish, fish, and sea mammals were being harvested from island habitats (Erlandson et al., 2011a and Erlandson et al., 2011b).

g., avalanches, debris flows, rock-falls, causing problems of particular relevance for protection forests services ( Brang et al., 2006 and Beghin et al., 2010), including water supply. Moreover, large fires at the rural–urban interface involve civil protection issues ( Höchtl et al., 2005 and Ascoli and Bovio, 2010) and increasing costs due to post-fire restoration ( Beghin et al.,

2010, Wohlgemuth et al., 2010 and Ascoli et al., 2013a). On the contrary, the second generation of large fires, e.g., in the south-western Alps in 1989–90, characterized by mixed severity effects, i.e., a mosaic of low, intermediate and high severity stand replacing phases, might promote structural and species diversity in formerly exploited forests (e.g., chestnut and beech coppice woodlands, conifer

plantations) that are now no more managed, thus accelerating LY2835219 the transition to alternative ecosystem states dominated by semi-natural ecological processes, e.g., Moretti et al. (2006), Maringer et al. (2012), Ascoli et al. (2013a), Fernandes et al. (2013), which is the aim of forest management in most unproductive forested areas of the Alps. Concerns about the long-term consequences of uncharacteristic fire regimes, and expected benefits from planning fire use, recently gave rise to a discussion about the suitability of implementing prescribed burning programmes in the Alpine environment (Lemonnier-Darcemont, 2003, Bernard-Laurent and Weber, 2007, Lyet et al., 2009, Valese et al., 2011b and Ascoli et al., 2013b). In particular, prescribed ABT 888 burning has been applied since the beginning of the 1980s over relatively large areas in the French Alps (e.g., ∼2000 ha yr−1 in the Department of Alpes Maritimes) both to regulate pastoral fire use (Fig. 8) and to abate fire risk by periodically reducing hazardous fuels in fuel Wilson disease protein breaks strategically placed in the landscape (Fernandes et al., 2013). Long-term results (>20

yrs) of prescribed burning programmes in the French Alps have shown a shift from a fire regime characterized by uncontrolled fires, usually on high fire danger days, with a high inter-annual variability in overall burnt area, to a prescribed burning regime of lower severity and on a yearly planned area (Réseau Brûlage Dirigé, 2012). Experimental prescribed burning for similar objectives has also been carried out in the Italian Alps (Ascoli and Bovio, 2013), both to prevent the surreptitious use of fire by shepherds and to preserve habitats of interest included in the Habitat Directive (HD) 92/43/EEC, such as Calluna heathlands (cod. HD: 4030) in the western Alps ( Ascoli et al., 2013b), eastern sub-Mediterranean dry grasslands (Scorzoneretalia villosae – cod. HD: 62A0) and lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis – cod. HD: 6510) in the eastern Alps ( Valese et al., 2011b).

To be sure whether

the immediate staining on the microscope slides would lead to the detection of the same number of nuclei compared to the staining with 1 h incubation, the two PD0332991 clinical trial staining methods were performed on the same hair roots and compared. Focus has been put on naturally shed hairs, mimicking forensic situations. There were no significant differences between the two staining methods (McNemar test, p = 1.00), except for one hair in which direct staining of the hair root on a microscope slide resulted in detection of less nuclei compared to the longer incubation method. Counting less than 20 nuclei, all hair roots but one resulted in full STR profiles. From the 49 hair roots without any visible nuclei, 3 resulted in a partial STR profile and 1 even in a full STR profile ( Table 2). One of the hair roots which resulted in a partial profile, showed presence of adhering material, presumably dandruff. Adhering material can contain DNA and could therefore result in a STR profile. In an optimal situation, hair roots without visible nuclei could be discarded. In 96% (94/98) of all cases where no nuclei were observed, no STR profile was obtained. However, in 4% of these cases, a full or partial STR profile could be obtained. Therefore, results of DAPI-staining should

always Saracatinib mw be considered in function of the importance of the evidential value of the found hair. If the hair is the only biological evidence in the forensic case, one might consider to submit the hair to STR analysis anyway, even if the staining is considered to be negative. If necessary, multiple hair roots showing the same characteristics can be pooled for STR analysis. In case the hair root did not yield a STR profile, the remainder of the hair can still be submitted to mitochondrial DNA analysis [16] and [17]. However, as STR analysis has a higher discriminative power compared to mitochondrial DNA analysis, the former is preferred. Ten hairs plucked from 1 donor were collected using the tape lifting kit, subsequently removed from the Pembrolizumab adhesive tape and directly

stained on microscope slides. In 8 of 10 cases, 21–50 nuclei were counted while in the remaining 2 cases, more than 50 nuclei were observed. In all cases, full STR profiles were obtained (data not shown). However, loss of nuclei after removing the hair root from the adhesive tape could be observed as the adhesive tape was re-examined under the fluorescence microscope and nuclei were found on the tape. Therefore, if adhesive tapes are used for collecting hairs from a crime scene, it can be interesting for STR analysis to include that part of the tape where the hair root was located. The presented fast screening method was applied in 36 forensic cases in which 279 hair roots were stained with DAPI directly on microscope slides (part II). 263 hair roots were quoted as negative.

5%, 9.5%, 3.8%, and 3.2% of the tested rodents, and in 5.8%, 1.7%, 0.6%, and 1.2% of the domestic animals ( Darwish et al., 1983). Antibodies specific for Sicilian and Naples viruses were detected in 27% to 70% of Pakistani military personnel by ELISA ( Bryan et al., 1996). In 1936, a viral strain was isolated from a patient presenting with a syndrome compatible with sandfly fever (Shortt, 1936). However this strain

was not characterized, JQ1 supplier either antigenically or genetically, and was finally lost (Bhatt et al., 1971). Sicilian virus was isolated in Maharastra state during an epidemic of febrile illness (Bhatt et al., 1971). In addition, nine strains of Sicilian virus and 11 strains of Naples virus

were isolated from Phlebotomus spp., while neutralizing antibodies against Naples virus were detected in human sera ( Goverdhan et al., 1976). Two seroprevalence studies conducted in 1976 and 1984 described the presence of antibodies against Sicilian and Naples virus at rates ranging from 2.7–6.25% and 1.25–12%, respectively using either PRNT (80) or Selleckchem Compound C HI tests (Gaidamovich et al., 1984 and Tesh et al., 1976). HI-based antibodies against Karimabad were reported in 11.25% of human sera. The geographic spread of sandfly-borne phleboviruses depends on the geographic distribution of Phlebotomus species, which are considerably influenced by climatic changes and environmental modifications ( Weaver and Reisen, 2010). Even under conservative and optimistic scenarios, future climate change is likely to increase air temperatures. At the end of this century, the number of hot days in central Europe is projected to reach conditions that are currently experienced in southern Europe. While heavy summer precipitation is expected

to increase in northeastern parts of Europe, it is likely to decrease in the south ( Beniston et al., 2007). In addition, changes in annual cold extremes are projected, whereby the largest relative warming is expected for northeastern Europe ( Goubanova and Li, 2007). These climatic changes may support a range shift and further regional establishment of certain sandfly species, including Forskolin mw P. mascittii. As an ectothermal arthropod, like other sandfly species, P. papatasi is unable to regulate its body temperature. Hence the species directly depends on the thermal conditions of its environment. Under laboratory conditions, changes in temperature and humidity affect the population dynamics of this species, which suggests that climate change is likely to extend the limits of its northern distribution ( Kasap and Alten, 2005). Regarding a northward shift, especially temperature constraints in the cold period and decreasing photoperiod are of main interest, as factors determine diapause of eggs and thus the survival of sandfly species.

The authors also noted that the effects of almitrine on chemosensitivity persisted despite plasma levels of the drug declining below these thresholds. Small increases in V˙E (∼11% above baseline) on room air were only observed when plasma concentrations of almitrine exceeded approximately 250 ng/mL. The ability of a carotid body stimulant to increase chemosensitivity without an accompanying increase in V˙E during

normoxia may reflect the limited role of the carotid body in modulating V˙E http://www.selleckchem.com/products/iwr-1-endo.html during normoxic conditions. Thus, potentiation of carotid body signaling in this scenario may only be evident when an individual is exposed to hypoxia and/or hypercapnia. The persistent effect of almitrine on chemosensitivity despite waning plasma levels may be due to the presence of an active metabolite

or tissue binding Ceritinib concentration of the drug within the peripheral chemoreceptors. The effects of almitrine on sleep-disordered breathing in humans have been evaluated with equivocal results (Hackett et al., 1987 and Mangin et al., 1983). Carotid body stimulation can stabilize breathing and decrease apneic events during sleep by increasing minute volume, thereby decreasing loop gain (Dempsey et al., 2012). Loop gain is an engineering term that describes the sensitivity of a variable system to perturbations. Loop gain comprises controller gain (i.e., chemoreceptors) and plant gain (i.e., the blood gas response to a change in ventilation). Almitrine has been evaluated in an animal model where the influence of loop gain on ventilatory stability is measured (Nakayama, 2002). Almitrine decreased plant gain by stimulating ventilation and was able to protect against ventilator-induced central apneas and hypopneas. Countering this stabilizing influence is the effect of almitrine on hypoxic chemosensitivity (i.e., controller gain). Thus, almitrine can increase controller gain, which would worsen sleep-disordered

breathing. The net effect of almitrine on sleep-disordered Protein tyrosine phosphatase breathing is likely to be dependent on the dose administered and the type of patient in question. Almitrine exerts beneficial effects on pulmonary gas exchange (increased P  aO2, and improved ventilation–perfusion ratios – V˙A/V˙Q matching) without increasing V˙E ( Barer et al., 1983, Hughes et al., 1983, Hughes et al., 1986 and Melot et al., 1989). The mechanism responsible for this effect is believed to be enhanced hypoxic pulmonary vasoconstriction (HPV). Almitrine improves V˙A/V˙Q matching in patients with COPD and increases pulmonary vascular resistance consistent with an effect on pulmonary vascular tone ( Melot et al., 1983a and Melot et al., 1983b). HPV is often depressed peri-operatively, so any new drug for this setting that normalizes HPV would be highly desirable.

5). Because core C4 does not lie at either extreme in thickness, the variations throughout

the impoundment tend to cancel out, hence the similarity in the two estimates of total sediment mass reported above. Downstream of the former power plant, core C4 is representative of the sediment deposit (Fig. 4). However, upstream of the former power plant, CCP-bearing sediment is absent and the sandy layers that are present have a higher dry bulk density. Because of these limiting assumptions, we caution that our calculation of mass accumulation for the entire impoundment be viewed as a general constraint on the Middle Cuyahoga River sediment load. The Middle Cuyahoga watershed and river have experienced tremendous anthropogenic impacts during the twentieth century, and the sediment deposited in the Gorge Dam impoundment selleckchem records those impacts. Changes Cilengitide clinical trial in sediment characteristics and watershed activities have allowed the sediment record to be divided into the following 3 time periods. The mud accumulating during the First Period (1912–1926) has low amounts of CCP, even though the coal-fired power-plant had begun production in 1912 (Fig. 8). The low CCP concentration may be due to low power plant production or better land containment of the CCP. Pb, Cr, and Zn concentrations

exceed the PEC levels in most samples and reflect the many industries and human activities that were well-established along the Cuyahoga River immediately upstream of the Gorge impoundment (Seguin and Seguin, 2000, Hannibal and Foos, 2003 and Whitman et al., 2010, p. 79; Vradenburg, 2012). Although leaded gasoline use was limited prior to the 1940s, lead use in paint was high in the 1910s and peaked in the 1920s (Filippelli et al., 2005). The Second

Period period (1926–1978) sediments have abundant CCP, high and variable metal concentration, and high magnetic concentration (Fig. 8). The strong direct relationship between CCP-bearing sediment and high magnetic susceptibility (K) values results from the abundant ferrimagnetic particles in CCP ( Rose, 1996). The source of much of the CCP in the sediment is the former coal-burning power-plant, because higher K values Phosphoglycerate kinase and thus greater amounts of CCP are found downstream of the former power plant ( Fig. 4). Trace metals are often found in relatively high concentrations in CCP and may become soluble and leached under sulfide rich and low pH conditions ( Jegadeesan et al., 2008 and Jones et al., 2012). The sediment in the Gorge Dam pool is anaerobic, as evidenced by the released of abundant methane gas during coring, and is favorable for sulfide formation. Through targeted sampling, the trace metal concentrations in the black mud were found to be 36–140% greater than in the CCP-bearing sediment. Thus, trace metals originally in the CCP may have leached out and attached to particles in the interbedded mud layers. However, CCP are not the only source of trace metals in the sediments.

Ginseng planting decreased the TOC concentrations and, subsequently, the Alp concentrations. The increase in the Ex-Al3+ in the summer and autumn might result from a decreased pH, NO3− surface accumulation, and the transformation of Alp into Ex-Al3+. Al toxicity might have an important impact on albic ginseng garden NVP-BGJ398 cell line soils, especially in the summer and autumn. All authors declare no conflicts of interest. Financial support for

this research was provided by the National Natural Science Foundation of China (No. 40903029) and International Foundation for Science (C4711-1). “
“Cancer is one of the most fatal diseases that poses a threat to human health worldwide [1]. A deviant regulation of apoptosis is required for cancer initiation, development, and metastasis [2]. Recent anticancer treatment, including chemotherapy, immunotherapy, radiation, and cytokines, primarily induce apoptosis in targeted cancer cells [3]. Apoptosis, a programmed cell death, is initiated through two main pathways: the exogenous

pathway, which is characterized by death receptor activation; and the endogenous pathway, which is characterized by mitochondrial destruction [4]. The tumor necrosis factor receptor superfamily triggers the membrane receptor aggregation and then recruits Fas associated death domain (FADD) and caspase-8 by binding of its specific ligand. Upon recruitment, caspase-8 becomes activated and initiates apoptosis through the direct cleavage of the downstream selleck kinase inhibitor effector caspases, particularly caspase-3 and -7. In the

mitochondrial pathway, apoptogenic factors, such as cytochrome c, second mitochondria-derived activator of caspases (Smac), or Suplatast tosilate apoptosis-inducing factor (AIF), are released into the cytosol from the mitochondria. Cytochrome c triggers the activation of caspase-9 by forming the cytochrome c/apoptotic protease-activating factor (Apaf-1)/caspase-9-containing apoptosome complex. Meanwhile, Smac promotes the activation of caspase by invaliding the inhibitory effects of the inhibitors of apoptosis (IAP) family [5], [6] and [7]. Combination treatments prove to be advantageous in treating malignancies that still partially respond to a single treatment [8]. Drugs have long been combined to treat diseases and reduce suffering; this long-standing history of drug combinations is clearly depicted in traditional Chinese medicines [9]. Panax ginseng has been long used for several thousand years in the Orient as a tonic, prophylactic, and restorative agent [10]. Sun ginseng (SG), a new type of ginseng that is processed by heating at specific pressures, contains approximately equal amounts of three major ginsenosides (RK1, Rg3, and Rg5). SG reportedly serves several functions, including radical scavenging and antitumor-promoting activities [11], [12] and [13].

We also analyzed the evolving patterns of shoreline change along the Danube delta coast on 177 cross profiles during the transition from

natural to anthropogenic conditions using the single surveys of 1856 (British Admiralty, 1861) and 1894 (CED, 1902) and shoreline changes between 1975/1979 and 2006 (SGH, 1975 and Vespremeanu-Stroe et al., 2007). Automatic extraction of rates was performed using the Digital Shoreline Analysis System (Thieler et al., 2009). Recent sedimentation rates at all our locations have been above or close the local relative sea level rise of ∼3 mm/yr (Table 2) when both siliciclastic and organic components are considered. However, millennial scale sedimentation rates (Table 3) are all below these recent rates with Selleckchem Torin 1 the lowest values at sites within the interior of the delta far from the main distributaries, such as lakes Fortuna (FO1) and Nebunu (NE1) or natural channels Perivolovca (P1) or Dranov Canal (along the former natural channel Cernetz; D2). The corresponding siliciclastic fluxes (Table 2 and Table 3 and Fig. 3) are between 1.5 and 8 times higher than the expected flux of 0.09–0.12 g/cm2 calculated by us using the available estimates for water flux transiting the interior of the delta (vide supra). This holds true for all depositional

environments ( Table 1 and Fig. 2 and Fig. 3) and Caspase inhibitor for all time intervals investigated. The larger than expected fluxes suggest that either a sampling design bias toward locations proximal to the sediment source (i.e., channels), turbid waters trapping inside the delta more than 10% of the sediment transported in suspension by the Danube or a combination of both. In this context, we note that any location in the delta is relatively proximal to a channel due to the high density of the channel network and that the siliciclastic flux in the most distal lake cored by us (Belciug) is still above the expected Tryptophan synthase 0.09–0.12 g/cm2. However, even if any bias was introduced by sampling, the pattern of increased

deposition near channels would mimic well the natural deposition pattern ( Antipa, 1915). The largest overall siliciclastic fluxes correspond to the post-WWII period (1954-present) with an average of 0.4 g/cm2. When only the post-damming interval is considered, siliciciclastic fluxes fall back to values not much higher than those measured for the long term, millennial time scales: 0.23 vs. 0.14–0.17 g/cm2 respectively. Post-WWII fluxes to locations on the delta plain near distributaries, secondary channels or canals were generally higher than fluxes toward lakes, either from cores collected at their shores or within the lake proper (Fig. 3), but this apparent relationship collapses in the most recent, post-damming period. And while large reductions in fluxes occurred at the delta plain marsh sites between these two recent intervals, at locations associated with lakes, the decrease in fluxes is less dramatic (Fig. 3).

3). In the first cycle between 6250 ± 250 and 2600 ± 250 years BP, sedimentation was slower (∼1 m/ka) compared to the second cycle after

1470 ± 60 years BP (∼2 m/ka). This depositional history shows that the Chilia I lobe developed in two phases. A smaller proto-Chilia distributary started the lobe growth after 6500 years BP in the same time as the Tulcea bayhead lobe grew adjacently to the south (Carozza et al., 2012b). Occurrence of benthic foraminifera (i.e., Ammonia sp.) find more at the base of our core indicates that the Pardina basin was connected to the sea at the time. Because contemporary deposits of the Tulcea lobe to the south record only freshwater fauna ( Carozza et al., 2012b) this connection of the Pardina basin to the Black Sea was probably located at the Chilia loess gap. The hiatus between the two deltaic cycles ( Fig. 3) indicates that the proto-Chilia distributary diminished its discharge or ceased to be active after ∼2600 years BP and was reactivated or rejuvenated after ∼1500 years BP. By the time that PD0332991 supplier this new distributary began to build a new lobe beyond the Chilia loess gap, the growth of Chilia I lobe was probably largely completed. Chilia II lobe presents a typical bayhead delta morphology (e.g., Bhattacharya and Walker, 1992)

with multiple distributaries bifurcating primarily at its apex at the Chilia loess gap (Fig. 2b). This channel network pattern, along with a lack of interdistributary ponds, suggests that the new lobe developed by filling the East Chilia basin in a sweeping and rapid west-to-east migration. Although most of the Chilia water flows now along several central anastomosing channels, natural levee deposits are less developed than in the older upstream lobe. Lack of below secondary channels intruding into the basins south or north of the East Chilia basin (Fig. 2c) suggests that the basin was completely confined as the Chilia II lobe grew. The Letea strandplain and the Jebrieni spit separated the East Chilia basin from the Black Sea whereas the Tulcea lobe extension into the Matita-Merhei basin

along with the Rosca-Suez strandplain confined the basin in the south and the lagoonal Sasic strandplain confined it in the north. The presence of marine fauna such as foraminifera (Ammonia sp.) and bivalves (Cardium edule) above loess deposits at the base of our core collected at the apex of the Chilia II lobe ( Fig. 2) indicates that the East Chilia basin was initially a lagoon connected to the Black Sea. Above the fine grained lagoon sediments, the deposits of the Chilia II lobe exhibit a typical but thin succession of fine prodelta deposits and delta front sands with interstratified muds that are capped by organic-rich fines of the delta plain and soil. A radiocarbon date at the base of the delta front deposits indicates that the Chilia II lobe started to grow at this proximal location at 800 ± 130 years BP ( Giosan et al., 2012).

, 2003). Most recorded sites were pointed out to researchers by locals (e.g., Nimuendaju, 2004). Though major phases of human occupation and environmental change have emerged from site research, most sites have not been investigated comprehensively, and there has been only limited coverage over Amazonia as a whole. Though only a tiny proportion of Amazonia has been examined, thousands of sites have been discovered in the diverse regions examined by researchers. As more areas are examined and more sites are found, new

regional cultures are being discovered (Fig. 1). Aerial survey was important in geographers’ early revelations about large wetland raised field systems (Denevan, 1966), but few sites of any kind have been mapped with instruments and even fewer with ground-probing geophysical technology (e.g., Bevan and Roosevelt, 2003, Roosevelt, 1991b and Roosevelt, PD98059 molecular weight 2007). check details Anthropic deposits that affect geomorphology over large areas are in principle detectable from the air or from space in many ways (e.g., El Baz and Wiseman, 2007). With such methods, we could better evaluate the patterning,

scope, and functioning of site complexes. Evidence of different cultures and land-management systems in Amazonia has come from stratigraphic analysis of sediments (e.g., Heckenberger, 2004, Iriarte et al., 2010, Morais and Neves, 2012, Neves, 2012, Piperno and Pearsall, 1998, Prumers,

2013, Roosevelt, 1991b, Roosevelt, 1997, Roosevelt et al., 1996, Rostain, 2010, Rostain, 2012 and Rostain, 2013). Excavation defines sites’ cultural components, layering, activity areas, and sequences of occupation. Soil processing to recover artifacts and ecofacts from strata gives evidence of specific past environments and economies and materials for dating. Where stratigraphy is not purposefully sampled, analyzed, and dated, questionable conclusions ensue, such as Pleistocene savannization and desertification (Whitmore and Prance, 1987) or megafaunal extinctions find more (Coltorti et al., 2012), unsupported by more comprehensive and critical studies (see Section ‘Environmental background’). And extrapolations not based on excavated cross-sections (van der Hammen and Absy, 1994:255, Fig. 2; Lombardo et al., 2013a, Fig. 2) do not accurately represent stratigraphy. Coring has been a main method for sampling offsite sediments to reconstruct past environments and land use. However, site formation processes and effectiveness of coring are seldom evaluated. Cores are often interpreted as direct evidence of regional climate change, without consideration of processes of local hydrology. For example, if an ancient water body dries up, this is interpreted as epochal climate change, though lake levels can change because of local hydrological or tectonic shifts (Colinvaux et al., 2000).